Chapter 9.2 · The eight Americas · Report

Eight types of neighborhood

Mean life expectancy for deaths in 2010 to 2015 runs from 74.7 to 82.1 years across eight overlapping types of census tract, built by k-means from 81,343 tracts on 7 measures of income, poverty, education, family structure, tenure, age and density, with no outcome among them.

Author: Vishal Singh
Affiliation: NYU Stern
Published: 9 October 2026
Updated: 28 October 2026

Every estimate of the chapter with its interval and every figure as a table, generated from the chapter's data files. Table n of this report is figure n of the chapter. The same report as Markdown: report.md.

Identification

Title

Eight types of neighborhood

Label

The eight Americas

Chapter

9.2 (Part IX, Reading the patterns; Reading the patterns)

Question

Can American tracts be sorted into a small number of types, and how far apart are their outcomes?

Dek

Grain

neighborhoods

Status

published

Published

9 October 2026

Updated

28 October 2026

Data sources

American Community Survey. ACS 5-year estimates 2019-2023 for 2020 tracts: income, poverty, education, households, tenure, age and population (the inputs), and race and ethnicity (compared by type, not an input); years: 2019-2023 (5-year); weights: ACS 2019-2023 tract population
Census TIGER/Line tracts. 2020 tract land area for population density; years: 2020; weights: none (land area)
CDC/ATSDR Social Vulnerability Index. CDC/ATSDR Social Vulnerability Index 2022: share of residents in group quarters, for the institutional-tract flag; years: 2022 release (ACS 2018-2022); weights: none (flag)
USALEEP life expectancy. NCHS small-area life expectancy at birth, deaths in 2010 to 2015, 2020 tracts (area-weighted); an outcome compared by type, not an input; years: 2010-2015; weights: ACS 2019-2023 tract population
Opportunity Atlas. Adult income rank, teen births and incarceration of children born 1978 to 1983 raised in families at the 25th income percentile, 2020 tracts (interpolated by land area); outcomes compared by type; years: 1978-1983 birth cohorts (2018 release); weights: ACS 2019-2023 tract population
CDC PLACES. CDC PLACES 2024 release (BRFSS 2022): diabetes, smoking, frequent mental distress and obesity among adults, modeled crude prevalence; outcomes compared by type; years: 2024 release (tracts); 2025 release (ZCTAs, 2023 data year); weights: ACS 2019-2023 tract population
Area Deprivation Index. Area Deprivation Index 2023 national rank, a profile column and not an input; years: 2023 release (version 4.0.1; built on ACS 2019-2023); weights: ACS 2019-2023 tract population
Published estimates from cited studies. The exposure effect quoted in the causal box (Chetty and Hendren 2018); years: as reported in each study; weights: as reported in the study

Canonical URL

https://vishalsingh.org/zipcode/eight-types-of-neighborhood

Markdown

https://vishalsingh.org/zipcode/eight-types-of-neighborhood/report.md

BibTeX

@misc{singh2026eighttypesofneighborhood,
  author = {Singh, Vishal},
  title = {Eight types of neighborhood},
  year = {2026},
  url = {https://vishalsingh.org/zipcode/eight-types-of-neighborhood},
  note = {In ZIP Code Destiny. Published 9 October 2026; updated 28 October 2026.}
}

Principal estimates

The facts the dek and the opening prose cite, in order of appearance. Every fact is in the table of all estimates below.

Estimand	Population	Period	Value	Interval	n	Weights	Source	Fact id
population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	deaths in 2010 to 2015	74.7	95% CI 74.2 to 75.1	4,595 tracts	ACS 2019-2023 tract population	USALEEP life expectancy	t8_le
population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	deaths in 2010 to 2015	82.1	95% CI 81.9 to 82.3	10,184 tracts	ACS 2019-2023 tract population	USALEEP life expectancy	t1_le
count of tracts in the typology	census tracts with every input, not institutional, with more residents than the floor	tract boundaries of 2020; inputs from ACS 2019-2023	81,343			none (full count)	American Community Survey	n_tracts
count of inputs of the typology (definition)	measures standardized and given to k-means	ACS 2019-2023, 2020 land area	7			none (definition)	American Community Survey	n_features
difference between the population-weighted mean life expectancy of type 1 minus type 8 (High-income owners minus High-poverty, single-parent), bootstrap interval over counties with shared draws	residents of the tracts of types 1 and 8 that have a life expectancy	deaths in 2010 to 2015	7.5	95% CI 7.1 to 7.9	14,779 tracts	ACS 2019-2023 tract population	USALEEP life expectancy	le_gap
count of inputs of the earlier typology (definition)	measures standardized and given to k-means in the earlier typology	2010 to 2023	13			none (definition)	American Community Survey	n_features_old
count of typed tracts that have all thirteen inputs of the earlier typology (the tracts of the comparison)	census tracts in the typology	tract inputs from 2010 to 2023	77,745			none (full count)	American Community Survey	n_compare
highest minus lowest population-weighted mean life expectancy across the groups of the chapter's earlier k-means fit on thirteen inputs, published until October 28, 2026, (the seven inputs of the typology plus the Black and Hispanic shares, life expectancy, the adult income rank, diabetes and smoking; same seed, groups and starts), on the tracts of the comparison, bootstrap interval over counties	residents of the typed tracts that have all thirteen inputs of the earlier typology	deaths in 2010 to 2015	10.0	95% CI 9.8 to 10.2	77,745 tracts	ACS 2019-2023 tract population	USALEEP life expectancy	le_spread_old
highest minus lowest population-weighted mean life expectancy across the groups of the eight types of this chapter, on the tracts of the comparison, bootstrap interval over counties	residents of the typed tracts that have all thirteen inputs of the earlier typology	deaths in 2010 to 2015	7.5	95% CI 7.1 to 7.9	77,745 tracts	ACS 2019-2023 tract population	USALEEP life expectancy	le_spread_c
mean silhouette of the eight types on a random sample of tracts drawn with a fixed seed	a random sample of census tracts in the typology	ACS 2019-2023, 2020 land area	0.19		20,000 tracts	none (each tract counts once)	American Community Survey	sil_k8
mean silhouette of an 8-group k-means fit to simulated data with no clusters: a multivariate normal with the correlations of the inputs and one draw per tract	a random sample of census tracts in the typology	ACS 2019-2023, 2020 land area	0.14		20,000 tracts	none (each tract counts once)	American Community Survey	sil_gauss

Findings

Across eight types of census tract formed from income, poverty, education, family structure, tenure, age and density alone, mean life expectancy for deaths in 2010 to 2015 runs from 74.7 (95% CI 74.2 to 75.1) years in the high-poverty, single-parent type to 82.1 (95% CI 81.9 to 82.3) years among high-income owners, a gap of 7.5 (95% CI 7.1 to 7.9) years. K-means builds the types from 7 measures of the American Community Survey (ACS) for 2019 to 2023 on 81,343 tracts, and none of the inputs is an outcome or a measure of race or ethnicity. The chapter's earlier typology had life expectancy, mobility, diabetes, smoking and the Black and Hispanic shares among its 13 inputs, and on the same 77,745 tracts its types spanned 10.0 (95% CI 9.8 to 10.2) years of life expectancy, against 7.5 (95% CI 7.1 to 7.9) years for the types here. The types are not sharply separated. The silhouette of the typology, a score of how well tracts fit their own type against the nearest other, is 0.19, against 0.14 for simulated data that contain no clusters.

The names are this book's labels for groups of tracts that look alike on the inputs. The overlap suggests that the types are regions of a continuum. This chapter builds the types, maps them by county, compares them on eight outcomes and on the Black and Hispanic shares of their residents, sets them beside the earlier fit and draws the overlap.

Three other chapters hold related material. The split of life-expectancy variance among states, counties and tracts, and a principal-components analysis of nine measures, are in Chapter 10.1, Gradients, slopes and variance. The parts of a deprivation index are in Chapter 1.1, What the deprivation index measures. A second clustering, built by k-means from the deprivation measures of the Area Deprivation Index, is in Chapter 10.2, Families of places. Neither clustering uses an outcome. The types here differ from those families because the share of older residents and population density are inputs. These two describe how a place is settled, and they set older owners, low-density owners and dense, college-educated renters apart from the other types.

How the types were built

The typology starts from the 85,396 tracts of the 2020 census. Puerto Rico's 981 tracts are left out, because the county map and the outcome measures cover only the states and the District of Columbia. A further 1,498 tracts lack at least one input or have no residents, and 1,541 are institutional tracts with a large share of residents in group quarters such as prisons, nursing homes or dormitories. The institutional flag comes from the group-quarters share in the Social Vulnerability Index, so it does not depend on whether a tract has a life expectancy estimate.

Another 33 tracts have 200 or fewer residents. What remains is 81,343 tracts, which hold 324.7 million residents, 97.7% of the residents of the states and the District of Columbia (Table 1). A tract enters the typology whether or not it has an outcome. Life expectancy exists for 77,763 of the typed tracts, and each outcome below is compared over the typed tracts that have it.

Table 1. The typology covers 81,343 of the 85,396 census tracts

The 7 inputs are the log of median household income, the poverty rate, the share of adults with a college degree, the single-parent share of households, the homeownership rate, the share of residents aged 65 and over and the log of population density, from the ACS for 2019 to 2023 and 2020 tract land area. The first five describe resources and family structure. Age and density describe how a place is settled, and they are not outcomes. Life expectancy, the adult income rank of children raised in low-income families, teen births, incarceration, diabetes, smoking, frequent mental distress and obesity are all outside the inputs, and so are the Black and Hispanic shares of residents.

Each input is standardized to mean zero and standard deviation one across tracts, and each tract counts once. K-means then places eight centers, assigns every tract to the nearest and repeats until the assignments settle, from many random starts. Eight is the book's choice, kept from the first edition, and the data do not select it. Across fits with 2 to 10 types the mean silhouette is highest at 2 types, where it is 0.27 against 0.24 for simulated data with no clusters. At no number of types do the tracts score more than 0.08 above that benchmark.

Refits on bootstrap resamples of tracts agree with the typology at a median of 0.95 on a scale where one means identical partitions and zero means chance, and the least similar refit agrees at 0.55. A refit that weights each tract by its population agrees at 0.84. The partition is therefore one of several that the data support. Chapter 10.2, Families of places sets out the method and its stability checks for a related clustering.

Types are numbered by the population-weighted mean of the first principal component of the inputs, a combined resource score that rises with income, college share and homeownership and falls with poverty and the single-parent share. The numbering runs from the highest score to the lowest and does not depend on the starting seed. The names are the book's labels for the profiles in Table 2, written into the build with a check that each profile still fits its name. A name describes what the inputs measure and names no race, ethnicity or outcome. The names label tracts and not the people who live in them. The chapter's label echoes the Eight Americas of Murray and colleagues, who divided the population by race and county to compare mortality.[1] These types group tracts by a profile of resources and settlement and share only the count of groups.

The types differ on age and density as well as income

Table 2 profiles each type. High-income owners hold 48.5 million residents, with tract median household incomes averaging 157 (95% CI 153 to 160) thousand dollars, a college share of 63.4%, a homeownership rate of 83.8% and a poverty rate of 4.0%.

Middle-income owners are the most populous type, with 79.5 million residents. Their incomes average 98 thousand dollars, the second highest of the eight, with a college share of 35.3% and a homeownership rate of 78.8%.

Table 2. High-income owners have the highest incomes and the high-poverty, single-parent type the highest poverty and single-parent shares, and their mean life expectancy differs by 7.5 years

Two owner types are set apart by settlement more than by income. Older owners hold 11.3 million residents, of whom 42.3% are aged 65 and over, in tracts where the homeownership rate is 78.9% and incomes average 84 thousand dollars. Low-density owners hold 52.3 million residents at a typical density of 55 (95% CI 53 to 57) residents per square mile, the lowest of the eight, with a homeownership rate of 80.1% and incomes averaging 68 thousand dollars.

Dense, college-educated renters hold 29.8 million residents at a typical density of 8,616 (95% CI 6,403 to 11,073) residents per square mile, the highest of the eight. Their college share of 56.6% is second only to that of high-income owners, and 36.1% of their homes are owner-occupied.

The moderate-income, mixed-tenure type holds 63.3 million residents, with incomes averaging 68 thousand dollars and a poverty rate of 14.5%. Its homeownership rate of 57.7% lies between those of the owner types and the renter types.

The last two types have similar incomes and poverty rates and differ in family structure and education. Lower-income renters hold 22.7 million residents, with a poverty rate of 29.8%, a homeownership rate of 35.8%, a single-parent share of 10.3% and a college share of 21.7%. The high-poverty, single-parent type holds 17.3 million, with a poverty rate of 32.4%, a homeownership rate of 35.2%, a single-parent share of 24.9% and a college share of 13.7%.

The Black and Hispanic shares are not inputs, and they differ across the types. Both are higher in each of the last three types than in any of the first five. The Black share averages 35.2% (95% CI 30.9% to 39.6%) and the Hispanic share 38.3% (95% CI 32.6% to 44.0%) in the high-poverty, single-parent type, against 5.0% and 9.6% among high-income owners and 5.7% and 8.1% among low-density owners. The moderate-income, mixed-tenure type has a Hispanic share of 32.0% (95% CI 27.8% to 36.1%), above its Black share. These shares describe who lives in each type and played no part in forming it.

Where the types are most common

Coloring each county by its most common type draws a map dominated by one type. Low-density owners are the most common type in 2,207 of the 3,110 counties that have a type, and middle-income owners in 438 (Table 3). Low-density owners lead in most counties of the South, the Midwest, the Plains and the Mountain West, and middle-income owners in most counties of Connecticut, Delaware, Hawaii and Rhode Island. The moderate-income, mixed-tenure type leads in 222 counties, most often in Texas and California. High-income owners lead in 103 counties and the high-poverty, single-parent type in 28, most of them in Texas, Georgia, Mississippi, South Dakota and Louisiana. The types other than the two most common lead mainly in counties with large populations.

Table 3. Low-density owners are the most common type in 2,207 of the 3,110 counties with a type, and middle-income owners in 438

A county's color is the type of its largest group of residents, and a county's residents are mixed. In the median county the modal type holds 68.1% of the typed residents. Across all counties with a type, 42.9% of typed residents live in a tract of their own county's modal type, which leaves more residents in a tract of another type.

Among the 173 counties with at least 100 typed tracts, a median of 3 types each hold at least 10% of the typed residents.

Counties are typed from their tracts. A county gets a type when its typed tracts hold at least 50% of its residents. 13 counties have no tract that is not institutional, has every input and has more than 200 residents. In another 20, typed tracts hold a smaller share. Both groups are gray on the map, and the tooltip gives the reason.

Residents are counted from the ACS. A tie in residents between two types goes to the lower-numbered type, and 1 county has one. Of the counties with a type, 485 rest on fewer than 3 typed tracts. Connecticut is drawn as its eight legacy counties, and Puerto Rico has no typed tract and is not drawn.

The high-poverty, single-parent type is least favorable on all eight outcomes

None of the eight outcomes is an input, so their order across the types is not built in (Table 4). The first tab holds life expectancy, the adult income rank of children raised in low-income families, and teen births and incarceration among the same Opportunity Atlas cohorts. The second holds diabetes, smoking, frequent mental distress and obesity among adults. The high-poverty, single-parent type has the least favorable mean on all eight. High-income owners have the most favorable mean on every outcome except diabetes, which is lowest among dense, college-educated renters (8.7% (95% CI 8.4% to 9.0%) of adults, against 9.4% (95% CI 9.2% to 9.5%)).

Table 4. The high-poverty, single-parent type has the least favorable mean on all eight outcomes, and high-income owners the most favorable on every outcome except diabetes

The share of women raised in low-income families who had a teen birth is 13.9% (95% CI 13.1% to 14.7%) among high-income owners and 38.9% (95% CI 37.8% to 40.0%) in the high-poverty, single-parent type. The share of children from those families who were incarcerated on Census Day 2010 is 1.3% (95% CI 1.2% to 1.4%) in the first type and 3.5% (95% CI 3.3% to 3.8%) in the last. The Opportunity Atlas measures share no file with any input. PLACES estimates are modeled partly from ACS covariates such as poverty and education, so the agreement between the types and the adult health measures is partly mechanical.

Between the two ends the types do not line up in one order. Dense, college-educated renters, numbered fifth, have a life expectancy of 80.3 (95% CI 79.9 to 80.6) years, which is 2.5 (95% CI 2.1 to 2.8) years above that of low-density owners, numbered fourth, although the two types sit at about the same place on the resource score. They also live longer than middle-income owners, at 79.6 (95% CI 79.5 to 79.7) years, and about as long as older owners, at 80.4 (95% CI 80.1 to 80.6) years, whose interval overlaps theirs. Life expectancy averages 77.8 (95% CI 77.7 to 77.9) years among low-density owners, 77.3 (95% CI 77.1 to 77.6) in the moderate-income, mixed-tenure type and 75.3 (95% CI 74.9 to 75.8) among lower-income renters. The intervals are narrow next to most gaps between types, since each type holds thousands of tracts. They describe how the means would vary with the sample of counties given the types, not with the choice of types.

The label foretells part of a tract's outcome and leaves the rest. The types account for 32% (95% CI 30% to 34%) of the population-weighted variance of tract life expectancy, 32% (95% CI 30% to 34%) of that of the teen-birth share and 8% (95% CI 7% to 9%) of that of the incarceration share. They account for 58% (95% CI 56% to 60%) of the variance of smoking and 59% (95% CI 57% to 61%) of that of frequent mental distress, two modeled PLACES measures whose agreement with the types is partly mechanical. Tracts of the same type still differ, and they differ most on incarceration.

The earlier types spread life expectancy wider, with outcomes among their inputs

The chapter's earlier typology used 13 inputs. It added the Black and Hispanic shares, life expectancy, the adult income rank, diabetes and smoking to the inputs here. The comparison refits it with the same k-means, seed and starts on the 77,745 typed tracts that have all of its inputs, which are the tracts it typed. It agrees with the types of this chapter at 0.41 on the agreement scale of the bootstrap refits, so the two partitions overlap in part.

On those tracts the earlier types span 10.0 (95% CI 9.8 to 10.2) years of life expectancy from the highest to the lowest type mean, and the types here span 7.5 (95% CI 7.1 to 7.9) years. The earlier types account for 49% (95% CI 47% to 51%) of the variance of tract life expectancy, against 32% (95% CI 30% to 34%) for the types here, and for 46% (95% CI 44% to 48%) of the variance of the teen-birth share, against 33% (95% CI 30% to 35%). Part of the earlier spread came from sorting tracts on life expectancy itself and on measures that move with it. The types here sort life expectancy and teen births with neither among their inputs, less sharply than the earlier fit did.

The types are not sharply separated

A silhouette of 0.19 is low, and two comparisons give it a scale. The first is simulated data with the correlations of the inputs and no clusters, in which k-means still finds eight groups. Their silhouette is 0.14, and 56.3% of the variance lies between the groups.

The tract data score 0.19 and 62.8%, with 37.2% of the variance within the types, a step above what a cloud without clusters gives. The benchmark is a guide and not a proof, because the simulated margins are symmetric and tract incomes, densities and rates are not.

The second comparison is the tracts themselves. In a sample of 20,000 tracts, 6.6% have a negative silhouette, which means that on average they sit closer to the tracts of another type than to those of their own.

Table 5 shows the overlap on the first two principal components, which capture 68.4% of the variance in the inputs. The first, 43.9%, weights income, college share, homeownership and the share of older adults positively and poverty and the single-parent share negatively, and it is the resource score that numbers the types. The second, 24.5%, weights density and college share positively and homeownership and the share of older adults negatively, and it separates dense renters from older and low-density owners. The plotted sample holds 6,000 tracts, and the ranges from the fifth to the ninety-fifth percentile of tracts overlap for every pair of neighboring types along the resource score. The overlap suggests that the types are bands of a continuum, and a tract near a border could have been assigned to the neighbor by a small change in the inputs. The resource score of this figure is a different object from the nine-measure analysis of Chapter 10.1, Gradients, slopes and variance, which uses other measures.

Table 5. Neighboring types overlap along the first component, and 6.6% of 20,000 sampled tracts sit nearer another type than their own

Causal evidenceMovers design

Whether growing up in a different place changes a child's adult income

The comparisons above describe tracts and cannot show that a tract's type changes anyone's life. Chetty and Hendren used federal tax records for children born in 1980 to 1988 whose families moved once between commuting zones, and compared children who moved at different ages, including siblings in the same family. The identifying assumption is that the selection that sends a family to a better or a worse place does not vary with the child's age at the move. They test it with sibling comparisons, with controls for changes in parental income and marital status, and with moves caused by displacement shocks. Children's adult income ranks move toward the ranks of children of permanent residents of the destination who had parents at the same income, by 0.04 percentile for each year of childhood spent there and each percentile by which the destination's ranks are higher.[2]

The design applies to commuting zones and counties, and its benchmark is permanent residents of the destination at the same parent income. It does not test the eight types, and it does not say that moving a child from one type to another changes an outcome by the gap between the types' means.

What these data cannot show

The types describe tracts, and every comparison is ecological: the life expectancy of the high-poverty, single-parent type is an average over tracts and says little about any one resident of one (ecological inference). The names are the book's labels for the profiles. A name such as high-poverty, single-parent summarizes two inputs of a profile that also has a Black share of 35.2% and a Hispanic share of 38.3%, and it does not describe the people who live there.

The types are built without outcomes, and the comparisons still do not show that a tract's resources or settlement produced any outcome. They show how closely conditions and outcomes move together across tracts. The measures come from different periods, with the ACS inputs for 2019 to 2023, life expectancy for deaths in 2010 to 2015, mobility for children born in 1978 to 1983 and PLACES built on 2022 survey data, so an outcome can predate the conditions it is compared with. The USALEEP estimates and the Opportunity Atlas ranks for 2020 tracts are interpolated from 2010 tracts by land area, not by population. The USALEEP estimates suit maps and gradients, the ACS file carries no margins of error, and PLACES values are modeled from covariates that include ACS measures and carry no intervals at the tract level.

The intervals in this chapter condition on the types. Tracts that lack an input are not typed. The 3,072 untyped tracts hold 7.7 million residents, and 39% of them lack a life expectancy estimate. Typed tracts without a life expectancy stay in the types and drop out of the life-expectancy comparisons.

The untyped tracts differ from the typed tracts. Their poverty rate averages 25.8% against 12.3%, and their Black share 19.4% against 11.9%. The residents of typed tracts, 97.7% of all residents, are therefore not a random sample of the country. The county map shows one type per county and hides the mix, and Puerto Rico is outside the typology and the map.

Tables

Table 1. The typology covers 81,343 of the 85,396 census tracts

Census tracts at each step from the 2020 census to the tracts with every input, counted at the first step that removes them

Step	Tracts
Tracts of the 2020 census	85,396
Puerto Rico (outside the county map and the outcome measures)	981
Other tracts missing at least one input or with no residents	1,498
Institutional tracts (25 percent or more of residents in group quarters)	1,541
Tracts with 200 or fewer residents	33
Tracts in the typology	81,343

Note: Puerto Rico is left out because the county map and the outcome measures cover the 50 states and DC. A tract is institutional when at least 25% of its residents live in group quarters such as prisons, nursing homes or dormitories (SVI 2022), or when it is a known chronic-care tract. Tracts with 200 or fewer residents are left out.

Note: A typed tract need not have an outcome. Life expectancy exists for 77,763 of the typed tracts, and each outcome is compared over the typed tracts that have it.

Source: 2020 census tracts with ACS 2019-2023 inputs, 2020 TIGER land area and SVI 2022 group-quarters shares; counts of tracts, full count

Data: vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/sample_flow.json

Table 2. High-income owners have the highest incomes and the high-poverty, single-parent type the highest poverty and single-parent shares, and their mean life expectancy differs by 7.5 years

Population-weighted mean of tract values by neighborhood type, types numbered by the first principal component of the inputs, largest first

Type	Residents (millions)	Tracts	Household income (thousands of dollars)	Poverty (%)	College degree (%)	Single-parent households (%)	Homeowners (%)	Aged 65 and over (%)	Density (residents per square mile)	Black (%)	Hispanic (%)	ADI national rank	Life expectancy (years)
High-income owners	48.5	10,661	157	4.0	63.4	4.6	83.8	17.3	2,017.3	5.0	9.6	17.3	82.1
Older owners	11.3	3,560	84	8.4	41.8	3.2	78.9	42.3	955.7	4.3	9.1	40.3	80.4
Middle-income owners	79.5	17,400	98	6.9	35.3	6.7	78.8	17.1	1,582.6	8.7	16.5	40.5	79.6
Low-density owners	52.3	15,491	68	13.0	20.4	7.0	80.1	20.8	55.33	5.7	8.1	68.2	77.8
Dense, college-educated renters	29.8	7,720	96	11.1	56.6	5.7	36.1	12.8	8,616.3	11.2	18.7	26.3	80.3
Moderate-income, mixed-tenure	63.3	14,865	68	14.5	22.3	13.4	57.7	13.7	3,362.8	16.9	32.0	56.9	77.3
Lower-income renters	22.7	6,759	43	29.8	21.7	10.3	35.8	14.7	4,376.0	24.8	28.5	67.4	75.3
High-poverty, single-parent	17.3	4,887	43	32.4	13.7	24.9	35.2	10.5	5,103.7	35.2	38.3	70.5	74.7

Note: The type names are the book's labels for groups of tracts that resemble one another on the inputs, not categories in the data. They describe income, poverty, education, family structure, tenure, age and density. No outcome and no measure of race or ethnicity is an input; the Black and Hispanic shares are shown to compare the composition of the types.

Note: Intervals for these cells and for the outcomes are bootstrap intervals over counties; the cells describe the tracts in each type.

Note: The ACS columns cover 2019 to 2023, and density is the weighted geometric mean of tract residents per square mile of 2020 land area, so a few very dense tracts do not set the value. Life expectancy is for deaths in 2010 to 2015 on tracts of 2020 (area-weighted), over the 77,763 typed tracts that have it. The ADI is the 2023 national rank (1 least and 100 most deprived).

Note: Black residents are Black alone and may be Hispanic; Hispanic residents are of any race.

Source: ACS 2019-2023, USALEEP life expectancy 2010-2015, Opportunity Atlas (children born 1978 to 1983), PLACES 2024 release and ADI 2023; tract values weighted by ACS population; population-weighted

Data: vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/type_profiles.json

Table 3. Low-density owners are the most common type in 2,207 of the 3,110 counties with a type, and middle-income owners in 438

Neighborhood type that holds the most residents in each county, tracts typed by k-means on 7 measures, ACS 2019-2023 population

No inline rows: the values of Table 3 are in /data/eight-types-of-neighborhood/modal_type_map.json.

Note: A county gets a type when its typed tracts hold at least 50% of its residents. 13 counties have no typed tract (a tract that is not institutional, has every input and has more than the floor of residents) and 20 have typed tracts that hold a smaller share, so they are gray with the reason in the tooltip. A county with a tie in residents takes the lower-numbered type, and 1 county has a tie. 485 counties with a type rest on fewer than 3 typed tracts.

Note: Connecticut is drawn as its eight legacy counties, with tracts assigned through the exact tract crosswalk. Puerto Rico is outside the typology and is not drawn.

Note: Colors mark the eight types and have no order.

Source: k-means types of tracts on seven ACS 2019-2023 measures and 2020 land area, summed to counties by ACS population; population-weighted

Data: vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/modal_type_map.json

Table 4. The high-poverty, single-parent type has the least favorable mean on all eight outcomes, and high-income owners the most favorable on every outcome except diabetes

Population-weighted mean of tract values by neighborhood type with 95% intervals from a bootstrap over counties, each panel in its own units

Table 4.1. Life expectancy, mobility and justice

Life expectancy and adult income rank are highest and teen births and incarceration lowest among high-income owners, and the reverse holds in the high-poverty, single-parent type

Life expectancy, the adult income rank, teen births and incarceration, population-weighted type means with 95% intervals

conf_high	conf_low	estimate	label	n	panel	type
82.30	81.93	82.13	High-income owners	10,184	Life expectancy at birth (years)	High-income owners
80.64	80.10	80.36	Older owners	3,221	Life expectancy at birth (years)	Older owners
79.73	79.47	79.60	Middle-income owners	16,921	Life expectancy at birth (years)	Middle-income owners
77.92	77.71	77.81	Low-density owners	15,201	Life expectancy at birth (years)	Low-density owners
80.62	79.92	80.31	Dense, college-educated renters	6,980	Life expectancy at birth (years)	Dense, college-educated renters
77.58	77.08	77.33	Moderate-income, mixed-tenure	14,393	Life expectancy at birth (years)	Moderate-income, mixed-tenure
75.82	74.88	75.34	Lower-income renters	6,268	Life expectancy at birth (years)	Lower-income renters
75.12	74.22	74.67	High-poverty, single-parent	4,595	Life expectancy at birth (years)	High-poverty, single-parent
50.12	49.23	49.68	High-income owners	10,651	Adult income rank of children from low-income families (percentile)	High-income owners
45.44	44.44	44.94	Older owners	3,543	Adult income rank of children from low-income families (percentile)	Older owners
45.00	44.42	44.71	Middle-income owners	17,392	Adult income rank of children from low-income families (percentile)	Middle-income owners
42.77	42.37	42.57	Low-density owners	15,490	Adult income rank of children from low-income families (percentile)	Low-density owners
45.08	43.73	44.44	Dense, college-educated renters	7,706	Adult income rank of children from low-income families (percentile)	Dense, college-educated renters
40.91	40.34	40.64	Moderate-income, mixed-tenure	14,860	Adult income rank of children from low-income families (percentile)	Moderate-income, mixed-tenure
38.43	37.36	37.89	Lower-income renters	6,757	Adult income rank of children from low-income families (percentile)	Lower-income renters
36.42	35.18	35.81	High-poverty, single-parent	4,884	Adult income rank of children from low-income families (percentile)	High-poverty, single-parent
14.67	13.10	13.86	High-income owners	10,629	Teen births among daughters of low-income parents (%)	High-income owners
19.97	18.31	19.12	Older owners	3,504	Teen births among daughters of low-income parents (%)	Older owners
22.93	21.84	22.38	Middle-income owners	17,382	Teen births among daughters of low-income parents (%)	Middle-income owners
27.88	27.21	27.54	Low-density owners	15,474	Teen births among daughters of low-income parents (%)	Low-density owners
22.10	19.14	20.51	Dense, college-educated renters	7,685	Teen births among daughters of low-income parents (%)	Dense, college-educated renters
30.43	29.15	29.77	Moderate-income, mixed-tenure	14,852	Teen births among daughters of low-income parents (%)	Moderate-income, mixed-tenure
35.04	32.46	33.76	Lower-income renters	6,745	Teen births among daughters of low-income parents (%)	Lower-income renters
39.98	37.77	38.86	High-poverty, single-parent	4,883	Teen births among daughters of low-income parents (%)	High-poverty, single-parent
1.35	1.18	1.26	High-income owners	10,648	Incarcerated on Census Day 2010, children of low-income parents (%)	High-income owners
1.86	1.63	1.75	Older owners	3,533	Incarcerated on Census Day 2010, children of low-income parents (%)	Older owners
1.90	1.76	1.83	Middle-income owners	17,390	Incarcerated on Census Day 2010, children of low-income parents (%)	Middle-income owners
1.98	1.89	1.94	Low-density owners	15,488	Incarcerated on Census Day 2010, children of low-income parents (%)	Low-density owners
2.14	1.69	1.90	Dense, college-educated renters	7,695	Incarcerated on Census Day 2010, children of low-income parents (%)	Dense, college-educated renters
2.59	2.36	2.48	Moderate-income, mixed-tenure	14,858	Incarcerated on Census Day 2010, children of low-income parents (%)	Moderate-income, mixed-tenure
3.25	2.83	3.04	Lower-income renters	6,754	Incarcerated on Census Day 2010, children of low-income parents (%)	Lower-income renters
3.81	3.28	3.54	High-poverty, single-parent	4,884	Incarcerated on Census Day 2010, children of low-income parents (%)	High-poverty, single-parent

Table 4.2. Adult health

Diabetes, smoking, mental distress and obesity are highest in the high-poverty, single-parent type and lowest among high-income owners, except diabetes, which is lowest among dense, college-educated renters

Modeled PLACES prevalence among adults, population-weighted type means with 95% intervals

conf_high	conf_low	estimate	label	n	panel	type
9.51	9.18	9.35	High-income owners	10,660	Diabetes among adults (%)	High-income owners
13.92	13.35	13.64	Older owners	3,560	Diabetes among adults (%)	Older owners
11.24	10.95	11.09	Middle-income owners	17,400	Diabetes among adults (%)	Middle-income owners
13.90	13.72	13.81	Low-density owners	15,491	Diabetes among adults (%)	Low-density owners
9.02	8.44	8.74	Dense, college-educated renters	7,719	Diabetes among adults (%)	Dense, college-educated renters
13.32	12.90	13.11	Moderate-income, mixed-tenure	14,865	Diabetes among adults (%)	Moderate-income, mixed-tenure
15.69	14.89	15.30	Lower-income renters	6,759	Diabetes among adults (%)	Lower-income renters
17.26	16.63	16.94	High-poverty, single-parent	4,887	Diabetes among adults (%)	High-poverty, single-parent
9.24	8.86	9.03	High-income owners	10,660	Smoking among adults (%)	High-income owners
11.57	10.98	11.28	Older owners	3,560	Smoking among adults (%)	Older owners
13.33	12.94	13.13	Middle-income owners	17,400	Smoking among adults (%)	Middle-income owners
18.24	18.02	18.13	Low-density owners	15,491	Smoking among adults (%)	Low-density owners
10.82	10.27	10.53	Dense, college-educated renters	7,719	Smoking among adults (%)	Dense, college-educated renters
16.68	16.04	16.36	Moderate-income, mixed-tenure	14,865	Smoking among adults (%)	Moderate-income, mixed-tenure
20.13	19.11	19.60	Lower-income renters	6,759	Smoking among adults (%)	Lower-income renters
22.65	21.39	22.00	High-poverty, single-parent	4,887	Smoking among adults (%)	High-poverty, single-parent
13.27	12.99	13.12	High-income owners	10,660	Frequent mental distress among adults (%)	High-income owners
13.39	12.95	13.18	Older owners	3,560	Frequent mental distress among adults (%)	Older owners
16.05	15.86	15.95	Middle-income owners	17,400	Frequent mental distress among adults (%)	Middle-income owners
17.70	17.55	17.62	Low-density owners	15,491	Frequent mental distress among adults (%)	Low-density owners
16.03	15.53	15.75	Dense, college-educated renters	7,719	Frequent mental distress among adults (%)	Dense, college-educated renters
18.73	18.46	18.60	Moderate-income, mixed-tenure	14,865	Frequent mental distress among adults (%)	Moderate-income, mixed-tenure
21.29	20.76	21.02	Lower-income renters	6,759	Frequent mental distress among adults (%)	Lower-income renters
22.36	21.91	22.14	High-poverty, single-parent	4,887	Frequent mental distress among adults (%)	High-poverty, single-parent
27.89	26.48	27.12	High-income owners	10,660	Obesity among adults (%)	High-income owners
30.42	29.27	29.83	Older owners	3,560	Obesity among adults (%)	Older owners
33.31	32.34	32.84	Middle-income owners	17,400	Obesity among adults (%)	Middle-income owners
38.11	37.77	37.95	Low-density owners	15,491	Obesity among adults (%)	Low-density owners
28.45	26.39	27.30	Dense, college-educated renters	7,719	Obesity among adults (%)	Dense, college-educated renters
37.30	35.91	36.63	Moderate-income, mixed-tenure	14,865	Obesity among adults (%)	Moderate-income, mixed-tenure
40.30	38.19	39.26	Lower-income renters	6,759	Obesity among adults (%)	Lower-income renters
43.84	41.87	42.89	High-poverty, single-parent	4,887	Obesity among adults (%)	High-poverty, single-parent

Note: No outcome is an input to the typology. PLACES estimates are modeled partly from ACS covariates such as poverty and education, so the agreement between the types and the adult health measures is partly mechanical. The Opportunity Atlas measures share no file with any input.

Note: Opportunity Atlas measures are for children born 1978 to 1983 raised in families at the 25th income percentile, interpolated from 2010 to 2020 tracts by land area, and tract population stands in for the number of children. Life expectancy is for deaths in 2010 to 2015 and covers 77,763 of the typed tracts. PLACES values are modeled crude prevalence for adults, with BRFSS 2022 data. Each panel uses the typed tracts that have the measure.

Note: Intervals show how the means would vary with the sample of counties, given the types; they do not include uncertainty about the typology itself (a bootstrap over counties; replicates and seed in the methods note).

Data: vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/type_outcomes.json

Table 5. Neighboring types overlap along the first component, and 6.6% of 20,000 sampled tracts sit nearer another type than their own

A random sample of tracts on the first two principal components of the 7 standardized inputs, colored by type, with each type's centroid labeled

No inline rows: the values of Table 5 are in /data/eight-types-of-neighborhood/pca_continuum.json.

Note: The dots are a random sample of 6,000 of the typed tracts drawn with a fixed seed (replicates and seed in the methods note); the components, the types and the centroids use every typed tract. Components are in standardized units, and their signs are set so that log income and log density rise with the first and second component.

Note: The first component weights income, college share, homeownership and the share of older adults positively and poverty and the single-parent share negatively. The second component weights density and college share positively and homeownership and the share of older adults negatively.

Source: k-means types of tracts on seven ACS 2019-2023 measures and 2020 land area; principal components of the standardized inputs; unweighted sample of tracts, centroids population-weighted

Data: vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/pca_continuum.json

All estimates

Every fact in facts.json (131), sorted by id. The same values as JSON: facts.json.

Fact id	Value	Unit	Estimand	Population	Period	Interval	n	Weights	Source	Note
age_old	65	years of age	definition: the age at and above which a resident counts as an older adult in the share-aged-65-and-over input	residents	2019-2023			none (definition)	American Community Survey
ari_boot_median	0.95	adjusted Rand index (1 = identical partitions, 0 = chance agreement)	agreement of the typology with the median of the refits on bootstrap resamples of tracts	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
ari_boot_min	0.55	adjusted Rand index (1 = identical partitions, 0 = chance agreement)	agreement of the typology with the lowest of the refits on bootstrap resamples of tracts	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
ari_old	0.41	adjusted Rand index (1 = identical partitions, 0 = chance agreement)	agreement of the typology with the chapter's earlier k-means fit on thirteen inputs, published until October 28, 2026, (the seven inputs of the typology plus the Black and Hispanic shares, life expectancy, the adult income rank, diabetes and smoking; same seed, groups and starts)	census tracts in the typology that have all thirteen inputs of the earlier typology	tract inputs from 2010 to 2023		77,745 tracts	none (each tract counts once)	American Community Survey
ari_weighted	0.84	adjusted Rand index (1 = identical partitions, 0 = chance agreement)	agreement of the typology with a refit that weights each tract by its population	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
big_min_tracts	100	tracts	definition: the least number of typed tracts for the types-per-county count	counties	2019-2023			none (definition)	American Community Survey
big_types_median	3	types	median across counties of the number of types that hold at least a tenth of the county's typed residents	counties with at least 100 typed tracts	2019-2023		173 counties	none (each county counts once)	American Community Survey
ch_exposure_yr	0.04	percentiles of adult income rank per year of childhood exposure, per percentile of difference in permanent residents' outcomes	exposure effect reported by Chetty and Hendren (2018, Quarterly Journal of Economics 133(3)): federal tax records, children born 1980 to 1988, baseline sample of one-time movers between commuting zones; movers design that compares children who moved at different ages, with sibling comparisons (family fixed effects) and moves caused by displacement shocks; the benchmark is the adult income rank of children of permanent residents of the destination at the same parent income; copied from the paper and not computed in this build	children in the study's baseline sample whose families moved once between commuting zones	children born 1980 to 1988, moves from 1997 to 2010			none (reported estimate)	Published estimates from cited studies	A published estimate, not a result of this build.
cover_min	50%	percent of a county's residents	definition: a county gets a modal type when its typed tracts hold at least this share of its residents	counties	2019-2023			none (definition)	American Community Survey
few_tracts	3	tracts	definition: a county with fewer typed tracts than this is flagged as resting on very few tracts	counties	2019-2023			none (definition)	American Community Survey
inst_gq_pct	25%	percent of a tract's residents	definition: a tract is institutional when at least this share of its residents live in group quarters (SVI 2022 ep_groupq)	census tracts	SVI 2022 (ACS 2018-2022)			none (definition)	CDC/ATSDR Social Vulnerability Index
k_best	2	types	number of types with the highest mean silhouette in the comparison	k-means fits compared for the silhouette	ACS 2019-2023, 2020 land area			none (definition)	American Community Survey
k_hi	10	types	definition: the most types in the silhouette comparison	k-means fits compared for the silhouette	ACS 2019-2023, 2020 land area			none (definition)	American Community Survey
k_lo	2	types	definition: the fewest types in the silhouette comparison	k-means fits compared for the silhouette	ACS 2019-2023, 2020 land area			none (definition)	American Community Survey
le_gap	7.5	years of life expectancy at birth	difference between the population-weighted mean life expectancy of type 1 minus type 8 (High-income owners minus High-poverty, single-parent), bootstrap interval over counties with shared draws	residents of the tracts of types 1 and 8 that have a life expectancy	deaths in 2010 to 2015	95% CI 7.1 to 7.9	14,779 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
le_spread_c	7.5	years of life expectancy at birth	highest minus lowest population-weighted mean life expectancy across the groups of the eight types of this chapter, on the tracts of the comparison, bootstrap interval over counties	residents of the typed tracts that have all thirteen inputs of the earlier typology	deaths in 2010 to 2015	95% CI 7.1 to 7.9	77,745 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
le_spread_old	10.0	years of life expectancy at birth	highest minus lowest population-weighted mean life expectancy across the groups of the chapter's earlier k-means fit on thirteen inputs, published until October 28, 2026, (the seven inputs of the typology plus the Black and Hispanic shares, life expectancy, the adult income rank, diabetes and smoking; same seed, groups and starts), on the tracts of the comparison, bootstrap interval over counties	residents of the typed tracts that have all thirteen inputs of the earlier typology	deaths in 2010 to 2015	95% CI 9.8 to 10.2	77,745 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
med_modal_share	68.1%	percent of a county's typed residents	median across counties of the share of typed residents who live in tracts of the county's modal type	counties with a modal type	2019-2023		3,110 counties	none (each county counts once)	American Community Survey
n_big	173	counties	count of counties with at least 100 typed tracts (the cutoff is part of the definition)	counties with at least 100 typed tracts	2019-2023			none (full count)	American Community Survey
n_compare	77,745	tracts	count of typed tracts that have all thirteen inputs of the earlier typology (the tracts of the comparison)	census tracts in the typology	tract inputs from 2010 to 2023			none (full count)	American Community Survey
n_counties_few	485	counties	count of counties with a modal type that rests on fewer than three typed tracts	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_counties_low_cover	20	counties	count of counties whose typed tracts hold under half of the county's residents	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_counties_no_tract	13	counties	count of counties with no tract that is not institutional, has every input and has more than the floor of residents	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_counties_typed	3,110	counties	count of counties with a modal type	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_county_ties	1	counties	count of counties where two types hold exactly the same number of typed residents (the county takes the lower-numbered type)	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_features	7	inputs	count of inputs of the typology (definition)	measures standardized and given to k-means	ACS 2019-2023, 2020 land area			none (definition)	American Community Survey
n_features_old	13	inputs	count of inputs of the earlier typology (definition)	measures standardized and given to k-means in the earlier typology	2010 to 2023			none (definition)	American Community Survey
n_le	77,763	tracts	count of typed tracts with a USALEEP life expectancy estimate (the tracts over which life expectancy is compared)	census tracts in the typology	deaths in 2010 to 2015			none (full count)	USALEEP life expectancy
n_modal_t1	103	counties	count of counties where type 1 (High-income owners) holds the most residents	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_modal_t3	438	counties	count of counties where type 3 (Middle-income owners) holds the most residents	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_modal_t4	2,207	counties	count of counties where type 4 (Low-density owners) holds the most residents	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_modal_t6	222	counties	count of counties where type 6 (Moderate-income, mixed-tenure) holds the most residents	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_modal_t8	28	counties	count of counties where type 8 (High-poverty, single-parent) holds the most residents	counties and county equivalents on the county map (3,143, Connecticut as eight legacy counties)	2019-2023			none (full count)	American Community Survey
n_sample	6,000	tracts	size of a random sample drawn with a fixed seed for the scatter plot	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (sample size)	American Community Survey
n_tracts	81,343	tracts	count of tracts in the typology	census tracts with every input, not institutional, with more residents than the floor	tract boundaries of 2020; inputs from ACS 2019-2023			none (full count)	American Community Survey
n_tracts_all	85,396	tracts	count of 2020 census tracts in the atlas	census tracts of the 2020 census (50 states, DC and Puerto Rico)	tract boundaries of 2020; inputs from ACS 2019-2023			none (full count)	American Community Survey
n_tracts_inst	1,541	tracts	count of tracts flagged institutional (SVI 2022 group-quarters share of 25 percent or more, plus one known tract)	census tracts of the 50 states and DC with every input	tract boundaries of 2020; inputs from ACS 2019-2023			none (full count)	American Community Survey
n_tracts_missing	1,498	tracts	count of tracts missing at least one of the seven inputs or with no residents	census tracts of the 50 states and DC	tract boundaries of 2020; inputs from ACS 2019-2023			none (full count)	American Community Survey
n_tracts_pr	981	tracts	count of Puerto Rico tracts, left out because the county map and the outcome measures cover the 50 states and DC	census tracts of Puerto Rico	tract boundaries of 2020; inputs from ACS 2019-2023			none (full count)	American Community Survey
n_tracts_small	33	tracts	count of tracts with the population floor or fewer residents	census tracts of the 50 states and DC with every input, not institutional	tract boundaries of 2020; inputs from ACS 2019-2023			none (full count)	American Community Survey
n_untyped	3,072	tracts	count of tracts missing an input, institutional or with the floor of residents or fewer	census tracts of the 50 states and DC that are not in the typology	2019-2023			none (full count)	American Community Survey
pc12_evr	68.4%	percent of the total variance of the standardized inputs	share of variance captured by the first two principal components	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
pc1_evr	43.9%	percent of the total variance of the standardized inputs	share of variance captured by the first principal component	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
pc2_evr	24.5%	percent of the total variance of the standardized inputs	share of variance captured by the second principal component	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
pop_floor	200	residents	definition: a tract with this many residents or fewer is left out of the typology	census tracts	2019-2023			none (definition)	American Community Survey
pop_in_modal	42.9%	percent of typed residents	share of residents who live in a tract of their own county's modal type	residents of typed tracts in counties with a modal type	2019-2023		81,314 tracts	none (full count of estimates)	American Community Survey
pop_typed_share	97.7%	percent of residents	residents of tracts in the typology as a share of all residents of the 50 states and DC	residents of the 50 states and DC	2019-2023		81,343 tracts	none (full count of estimates)	American Community Survey
r2_jail	8%	percent of the population-weighted variance of tract incarceration share	R squared of the eight type means: variance between types over total variance of the tract measure, bootstrap interval over counties	residents of the tracts in the typology that have the measure	children born 1978 to 1983, incarceration on April 1, 2010	95% CI 7% to 9%	81,250 tracts	ACS 2019-2023 tract population	Opportunity Atlas
r2_le	32%	percent of the population-weighted variance of tract life expectancy	R squared of the eight type means: variance between types over total variance of the tract measure, bootstrap interval over counties	residents of the tracts in the typology that have the measure	deaths in 2010 to 2015	95% CI 30% to 34%	77,763 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
r2_le_c	32%	percent of the population-weighted variance of tract life expectancy	R squared of the group means of the eight types of this chapter on the tracts of the comparison that have the measure, bootstrap interval over counties	residents of the typed tracts that have all thirteen inputs of the earlier typology	deaths in 2010 to 2015	95% CI 30% to 34%	77,745 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
r2_le_old	49%	percent of the population-weighted variance of tract life expectancy	R squared of the group means of the chapter's earlier k-means fit on thirteen inputs, published until October 28, 2026, (the seven inputs of the typology plus the Black and Hispanic shares, life expectancy, the adult income rank, diabetes and smoking; same seed, groups and starts) on the tracts of the comparison that have the measure, bootstrap interval over counties	residents of the typed tracts that have all thirteen inputs of the earlier typology	deaths in 2010 to 2015	95% CI 47% to 51%	77,745 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
r2_mhlth	59%	percent of the population-weighted variance of tract frequent-mental-distress rate	R squared of the eight type means: variance between types over total variance of the tract measure, bootstrap interval over counties	residents of the tracts in the typology that have the measure	PLACES 2024 release, BRFSS 2022	95% CI 57% to 61%	81,341 tracts	ACS 2019-2023 tract population	CDC PLACES
r2_smk	58%	percent of the population-weighted variance of tract smoking rate	R squared of the eight type means: variance between types over total variance of the tract measure, bootstrap interval over counties	residents of the tracts in the typology that have the measure	PLACES 2024 release, BRFSS 2022	95% CI 56% to 60%	81,341 tracts	ACS 2019-2023 tract population	CDC PLACES
r2_teen	32%	percent of the population-weighted variance of tract teen-birth share	R squared of the eight type means: variance between types over total variance of the tract measure, bootstrap interval over counties	residents of the tracts in the typology that have the measure	children born 1978 to 1983	95% CI 30% to 34%	81,154 tracts	ACS 2019-2023 tract population	Opportunity Atlas
r2_teen_c	33%	percent of the population-weighted variance of tract teen-birth share	R squared of the group means of the eight types of this chapter on the tracts of the comparison that have the measure, bootstrap interval over counties	residents of the typed tracts that have all thirteen inputs of the earlier typology	children born 1978 to 1983	95% CI 30% to 35%	77,687 tracts	ACS 2019-2023 tract population	Opportunity Atlas
r2_teen_old	46%	percent of the population-weighted variance of tract teen-birth share	R squared of the group means of the chapter's earlier k-means fit on thirteen inputs, published until October 28, 2026, (the seven inputs of the typology plus the Black and Hispanic shares, life expectancy, the adult income rank, diabetes and smoking; same seed, groups and starts) on the tracts of the comparison that have the measure, bootstrap interval over counties	residents of the typed tracts that have all thirteen inputs of the earlier typology	children born 1978 to 1983	95% CI 44% to 48%	77,687 tracts	ACS 2019-2023 tract population	Opportunity Atlas
sil_best	0.27	silhouette (-1 to 1)	mean silhouette of the k-means fit (10 starts) with the number of types that scores highest	a random sample of census tracts in the typology	ACS 2019-2023, 2020 land area		20,000 tracts	none (each tract counts once)	American Community Survey
sil_best_bench	0.24	silhouette (-1 to 1)	mean silhouette of the same number of k-means groups (10 starts) in simulated data with no clusters: a multivariate normal with the correlations of the inputs and one draw per tract	a random sample of census tracts in the typology	ACS 2019-2023, 2020 land area		20,000 tracts	none (each tract counts once)	American Community Survey
sil_gauss	0.14	silhouette (-1 to 1)	mean silhouette of an 8-group k-means fit to simulated data with no clusters: a multivariate normal with the correlations of the inputs and one draw per tract	a random sample of census tracts in the typology	ACS 2019-2023, 2020 land area		20,000 tracts	none (each tract counts once)	American Community Survey
sil_k8	0.19	silhouette (-1 to 1)	mean silhouette of the eight types on a random sample of tracts drawn with a fixed seed	a random sample of census tracts in the typology	ACS 2019-2023, 2020 land area		20,000 tracts	none (each tract counts once)	American Community Survey
sil_margin_max	0.08	silhouette (-1 to 1)	largest difference, over fits with 2 to 10 types, between the mean silhouette of the tracts and that of the simulated data with no clusters	a random sample of census tracts in the typology	ACS 2019-2023, 2020 land area		20,000 tracts	none (each tract counts once)	American Community Survey
sil_neg_share	6.6%	percent of sampled tracts	share of sampled tracts with a negative silhouette (nearer to another type than to their own)	a random sample of census tracts in the typology	ACS 2019-2023, 2020 land area		20,000 tracts	none (each tract counts once)	American Community Survey
sil_sample	20,000	tracts	size of the random sample of tracts, drawn with a fixed seed, on which the silhouettes are computed	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (sample size)	American Community Survey
ss_between	62.8%	percent of the total variance of the standardized inputs	share of total variance of the standardized inputs that lies between the eight types	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
ss_between_gauss	56.3%	percent of the total variance of the standardized inputs	share of variance between eight k-means groups in simulated data with no clusters (multivariate normal with the correlations of the inputs)	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
ss_within	37.2%	percent of the total variance of the standardized inputs	share of total variance of the standardized inputs that lies within the eight types	census tracts in the typology	ACS 2019-2023, 2020 land area		81,343 tracts	none (each tract counts once)	American Community Survey
t1_blk	5.0%	percent of residents who are Black alone, Hispanic residents included	population-weighted mean of the tract Black share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	2019-2023	95% CI 4.3% to 5.7%	10,661 tracts	ACS 2019-2023 tract population	American Community Survey
t1_col	63.4%	percent of adults 25 and over with a bachelor's degree or more	population-weighted mean of the tract college share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	2019-2023	95% CI 62.5% to 64.1%	10,661 tracts	ACS 2019-2023 tract population	American Community Survey
t1_diab	9.4%	percent of adults with diabetes (modeled)	population-weighted mean of the tract diabetes rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	PLACES 2024 release, BRFSS 2022	95% CI 9.2% to 9.5%	10,660 tracts	ACS 2019-2023 tract population	CDC PLACES
t1_his	9.6%	percent of residents who are Hispanic of any race	population-weighted mean of the tract Hispanic share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	2019-2023	95% CI 8.7% to 10.5%	10,661 tracts	ACS 2019-2023 tract population	American Community Survey
t1_income	157	thousands of dollars of tract median household income	population-weighted mean of the tract tract median household income over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	2019-2023	95% CI 153 to 160	10,661 tracts	ACS 2019-2023 tract population	American Community Survey
t1_jail	1.3%	percent of children raised in low-income families incarcerated on Census Day 2010	population-weighted mean of the tract incarceration share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	children born 1978 to 1983, incarceration on April 1, 2010	95% CI 1.2% to 1.4%	10,648 tracts	ACS 2019-2023 tract population	Opportunity Atlas
t1_le	82.1	years of life expectancy at birth	population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	deaths in 2010 to 2015	95% CI 81.9 to 82.3	10,184 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t1_own	83.8%	percent of occupied homes that are owner-occupied	population-weighted mean of the tract homeownership rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	2019-2023	95% CI 83.0% to 84.7%	10,661 tracts	ACS 2019-2023 tract population	American Community Survey
t1_pop	48.5 million	residents	sum of ACS 2019-2023 tract population over the tracts of the type	residents of the tracts of type 1 (High-income owners)	2019-2023		10,661 tracts	none (full count of estimates)	American Community Survey
t1_pov	4.0%	percent of residents below the poverty line	population-weighted mean of the tract poverty rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	2019-2023	95% CI 3.9% to 4.1%	10,661 tracts	ACS 2019-2023 tract population	American Community Survey
t1_teen	13.9%	percent of women raised in low-income families who had a teen birth	population-weighted mean of the tract teen-birth share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 1 (High-income owners) that have the measure	children born 1978 to 1983	95% CI 13.1% to 14.7%	10,629 tracts	ACS 2019-2023 tract population	Opportunity Atlas
t2_income	84	thousands of dollars of tract median household income	population-weighted mean of the tract tract median household income over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 2 (Older owners) that have the measure	2019-2023	95% CI 82 to 86	3,560 tracts	ACS 2019-2023 tract population	American Community Survey
t2_le	80.4	years of life expectancy at birth	population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 2 (Older owners) that have the measure	deaths in 2010 to 2015	95% CI 80.1 to 80.6	3,221 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t2_own	78.9%	percent of occupied homes that are owner-occupied	population-weighted mean of the tract homeownership rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 2 (Older owners) that have the measure	2019-2023	95% CI 78.0% to 79.7%	3,560 tracts	ACS 2019-2023 tract population	American Community Survey
t2_p65	42.3%	percent of residents aged 65 and over	population-weighted mean of the tract share aged 65 and over over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 2 (Older owners) that have the measure	2019-2023	95% CI 40.8% to 43.8%	3,560 tracts	ACS 2019-2023 tract population	American Community Survey
t2_pop	11.3 million	residents	sum of ACS 2019-2023 tract population over the tracts of the type	residents of the tracts of type 2 (Older owners)	2019-2023		3,560 tracts	none (full count of estimates)	American Community Survey
t3_col	35.3%	percent of adults 25 and over with a bachelor's degree or more	population-weighted mean of the tract college share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 3 (Middle-income owners) that have the measure	2019-2023	95% CI 34.9% to 35.7%	17,400 tracts	ACS 2019-2023 tract population	American Community Survey
t3_income	98	thousands of dollars of tract median household income	population-weighted mean of the tract tract median household income over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 3 (Middle-income owners) that have the measure	2019-2023	95% CI 97 to 99	17,400 tracts	ACS 2019-2023 tract population	American Community Survey
t3_le	79.6	years of life expectancy at birth	population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 3 (Middle-income owners) that have the measure	deaths in 2010 to 2015	95% CI 79.5 to 79.7	16,921 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t3_own	78.8%	percent of occupied homes that are owner-occupied	population-weighted mean of the tract homeownership rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 3 (Middle-income owners) that have the measure	2019-2023	95% CI 78.4% to 79.2%	17,400 tracts	ACS 2019-2023 tract population	American Community Survey
t3_pop	79.5 million	residents	sum of ACS 2019-2023 tract population over the tracts of the type	residents of the tracts of type 3 (Middle-income owners)	2019-2023		17,400 tracts	none (full count of estimates)	American Community Survey
t4_blk	5.7%	percent of residents who are Black alone, Hispanic residents included	population-weighted mean of the tract Black share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 4 (Low-density owners) that have the measure	2019-2023	95% CI 5.3% to 6.1%	15,491 tracts	ACS 2019-2023 tract population	American Community Survey
t4_dens	55	residents per square mile of land	population-weighted geometric mean of tract density (exponential of the weighted mean of log density), bootstrap interval over counties	residents of the tracts of type 4 (Low-density owners)	2019-2023 population, 2020 land area	95% CI 53 to 57	15,491 tracts	ACS 2019-2023 tract population	American Community Survey
t4_his	8.1%	percent of residents who are Hispanic of any race	population-weighted mean of the tract Hispanic share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 4 (Low-density owners) that have the measure	2019-2023	95% CI 7.6% to 8.7%	15,491 tracts	ACS 2019-2023 tract population	American Community Survey
t4_income	68	thousands of dollars of tract median household income	population-weighted mean of the tract tract median household income over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 4 (Low-density owners) that have the measure	2019-2023	95% CI 67 to 68	15,491 tracts	ACS 2019-2023 tract population	American Community Survey
t4_le	77.8	years of life expectancy at birth	population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 4 (Low-density owners) that have the measure	deaths in 2010 to 2015	95% CI 77.7 to 77.9	15,201 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t4_own	80.1%	percent of occupied homes that are owner-occupied	population-weighted mean of the tract homeownership rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 4 (Low-density owners) that have the measure	2019-2023	95% CI 79.9% to 80.3%	15,491 tracts	ACS 2019-2023 tract population	American Community Survey
t4_pop	52.3 million	residents	sum of ACS 2019-2023 tract population over the tracts of the type	residents of the tracts of type 4 (Low-density owners)	2019-2023		15,491 tracts	none (full count of estimates)	American Community Survey
t5_col	56.6%	percent of adults 25 and over with a bachelor's degree or more	population-weighted mean of the tract college share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 5 (Dense, college-educated renters) that have the measure	2019-2023	95% CI 54.9% to 58.3%	7,720 tracts	ACS 2019-2023 tract population	American Community Survey
t5_dens	8,616	residents per square mile of land	population-weighted geometric mean of tract density (exponential of the weighted mean of log density), bootstrap interval over counties	residents of the tracts of type 5 (Dense, college-educated renters)	2019-2023 population, 2020 land area	95% CI 6,403 to 11,073	7,720 tracts	ACS 2019-2023 tract population	American Community Survey
t5_diab	8.7%	percent of adults with diabetes (modeled)	population-weighted mean of the tract diabetes rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 5 (Dense, college-educated renters) that have the measure	PLACES 2024 release, BRFSS 2022	95% CI 8.4% to 9.0%	7,719 tracts	ACS 2019-2023 tract population	CDC PLACES
t5_le	80.3	years of life expectancy at birth	population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 5 (Dense, college-educated renters) that have the measure	deaths in 2010 to 2015	95% CI 79.9 to 80.6	6,980 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t5_own	36.1%	percent of occupied homes that are owner-occupied	population-weighted mean of the tract homeownership rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 5 (Dense, college-educated renters) that have the measure	2019-2023	95% CI 34.6% to 37.7%	7,720 tracts	ACS 2019-2023 tract population	American Community Survey
t5_pop	29.8 million	residents	sum of ACS 2019-2023 tract population over the tracts of the type	residents of the tracts of type 5 (Dense, college-educated renters)	2019-2023		7,720 tracts	none (full count of estimates)	American Community Survey
t5_t4_le_gap	2.5	years of life expectancy at birth	difference between the population-weighted mean life expectancy of type 5 minus type 4 (Dense, college-educated renters minus Low-density owners), bootstrap interval over counties with shared draws	residents of the tracts of types 5 and 4 that have a life expectancy	deaths in 2010 to 2015	95% CI 2.1 to 2.8	22,181 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t6_his	32.0%	percent of residents who are Hispanic of any race	population-weighted mean of the tract Hispanic share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 6 (Moderate-income, mixed-tenure) that have the measure	2019-2023	95% CI 27.8% to 36.1%	14,865 tracts	ACS 2019-2023 tract population	American Community Survey
t6_income	68	thousands of dollars of tract median household income	population-weighted mean of the tract tract median household income over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 6 (Moderate-income, mixed-tenure) that have the measure	2019-2023	95% CI 67 to 69	14,865 tracts	ACS 2019-2023 tract population	American Community Survey
t6_le	77.3	years of life expectancy at birth	population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 6 (Moderate-income, mixed-tenure) that have the measure	deaths in 2010 to 2015	95% CI 77.1 to 77.6	14,393 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t6_own	57.7%	percent of occupied homes that are owner-occupied	population-weighted mean of the tract homeownership rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 6 (Moderate-income, mixed-tenure) that have the measure	2019-2023	95% CI 56.6% to 58.7%	14,865 tracts	ACS 2019-2023 tract population	American Community Survey
t6_pop	63.3 million	residents	sum of ACS 2019-2023 tract population over the tracts of the type	residents of the tracts of type 6 (Moderate-income, mixed-tenure)	2019-2023		14,865 tracts	none (full count of estimates)	American Community Survey
t6_pov	14.5%	percent of residents below the poverty line	population-weighted mean of the tract poverty rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 6 (Moderate-income, mixed-tenure) that have the measure	2019-2023	95% CI 14.3% to 14.6%	14,865 tracts	ACS 2019-2023 tract population	American Community Survey
t7_col	21.7%	percent of adults 25 and over with a bachelor's degree or more	population-weighted mean of the tract college share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 7 (Lower-income renters) that have the measure	2019-2023	95% CI 20.9% to 22.5%	6,759 tracts	ACS 2019-2023 tract population	American Community Survey
t7_le	75.3	years of life expectancy at birth	population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 7 (Lower-income renters) that have the measure	deaths in 2010 to 2015	95% CI 74.9 to 75.8	6,268 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t7_own	35.8%	percent of occupied homes that are owner-occupied	population-weighted mean of the tract homeownership rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 7 (Lower-income renters) that have the measure	2019-2023	95% CI 33.6% to 38.0%	6,759 tracts	ACS 2019-2023 tract population	American Community Survey
t7_pop	22.7 million	residents	sum of ACS 2019-2023 tract population over the tracts of the type	residents of the tracts of type 7 (Lower-income renters)	2019-2023		6,759 tracts	none (full count of estimates)	American Community Survey
t7_pov	29.8%	percent of residents below the poverty line	population-weighted mean of the tract poverty rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 7 (Lower-income renters) that have the measure	2019-2023	95% CI 29.3% to 30.4%	6,759 tracts	ACS 2019-2023 tract population	American Community Survey
t7_sp	10.3%	percent of households that are single-parent households	population-weighted mean of the tract single-parent share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 7 (Lower-income renters) that have the measure	2019-2023	95% CI 10.1% to 10.6%	6,759 tracts	ACS 2019-2023 tract population	American Community Survey
t8_blk	35.2%	percent of residents who are Black alone, Hispanic residents included	population-weighted mean of the tract Black share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	2019-2023	95% CI 30.9% to 39.6%	4,887 tracts	ACS 2019-2023 tract population	American Community Survey
t8_col	13.7%	percent of adults 25 and over with a bachelor's degree or more	population-weighted mean of the tract college share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	2019-2023	95% CI 13.1% to 14.3%	4,887 tracts	ACS 2019-2023 tract population	American Community Survey
t8_his	38.3%	percent of residents who are Hispanic of any race	population-weighted mean of the tract Hispanic share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	2019-2023	95% CI 32.6% to 44.0%	4,887 tracts	ACS 2019-2023 tract population	American Community Survey
t8_jail	3.5%	percent of children raised in low-income families incarcerated on Census Day 2010	population-weighted mean of the tract incarceration share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	children born 1978 to 1983, incarceration on April 1, 2010	95% CI 3.3% to 3.8%	4,884 tracts	ACS 2019-2023 tract population	Opportunity Atlas
t8_le	74.7	years of life expectancy at birth	population-weighted mean of the tract life expectancy over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	deaths in 2010 to 2015	95% CI 74.2 to 75.1	4,595 tracts	ACS 2019-2023 tract population	USALEEP life expectancy
t8_own	35.2%	percent of occupied homes that are owner-occupied	population-weighted mean of the tract homeownership rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	2019-2023	95% CI 32.5% to 37.9%	4,887 tracts	ACS 2019-2023 tract population	American Community Survey
t8_pop	17.3 million	residents	sum of ACS 2019-2023 tract population over the tracts of the type	residents of the tracts of type 8 (High-poverty, single-parent)	2019-2023		4,887 tracts	none (full count of estimates)	American Community Survey
t8_pov	32.4%	percent of residents below the poverty line	population-weighted mean of the tract poverty rate over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	2019-2023	95% CI 31.7% to 33.2%	4,887 tracts	ACS 2019-2023 tract population	American Community Survey
t8_sp	24.9%	percent of households that are single-parent households	population-weighted mean of the tract single-parent share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	2019-2023	95% CI 24.6% to 25.3%	4,887 tracts	ACS 2019-2023 tract population	American Community Survey
t8_teen	38.9%	percent of women raised in low-income families who had a teen birth	population-weighted mean of the tract teen-birth share over the tracts of the type, bootstrap interval over counties	residents of the tracts of type 8 (High-poverty, single-parent) that have the measure	children born 1978 to 1983	95% CI 37.8% to 40.0%	4,883 tracts	ACS 2019-2023 tract population	Opportunity Atlas
total_pop	324.7 million	residents	sum of ACS 2019-2023 tract population over the tracts in the typology	residents of the tracts in the typology	2019-2023		81,343 tracts	none (full count of estimates)	American Community Survey
type_share_min	10%	percent of a county's typed residents	definition: a type is present in a county when it holds at least this share of the typed residents	counties	2019-2023			none (definition)	American Community Survey
typed_blk	11.9%	percent of residents who are Black alone, Hispanic residents included	population-weighted mean of the tract Black share over the tracts in the typology	residents of the tracts in the typology that have the measure	2019-2023		81,343 tracts	ACS 2019-2023 tract population	American Community Survey
typed_pov	12.3%	percent of residents below the poverty line	population-weighted mean of the tract poverty rate over the tracts in the typology	residents of the tracts in the typology that have the measure	2019-2023		81,343 tracts	ACS 2019-2023 tract population	American Community Survey
untyped_blk	19.4%	percent of residents who are Black alone, Hispanic residents included	population-weighted mean of the tract Black share over the tracts not in the typology	residents of the tracts not in the typology that have the measure	2019-2023		2,268 tracts	ACS 2019-2023 tract population	American Community Survey
untyped_no_le	39%	percent of tracts	share of the tracts not in the typology that have no USALEEP life expectancy estimate	census tracts of the 50 states and DC that are not in the typology	deaths in 2010 to 2015		3,072 tracts	none (each tract counts once)	USALEEP life expectancy
untyped_pop	7.7 million	residents	sum of ACS 2019-2023 tract population over the tracts not in the typology	residents of the tracts of the 50 states and DC that are not in the typology	2019-2023		3,072 tracts	none (full count of estimates)	American Community Survey
untyped_pov	25.8%	percent of residents below the poverty line	population-weighted mean of the tract poverty rate over the tracts not in the typology	residents of the tracts not in the typology that have the measure	2019-2023		2,078 tracts	ACS 2019-2023 tract population	American Community Survey

Definitions

K-means: A method that sorts places into a chosen number of groups so that places in a group resemble one another on the measures used. The analyst sets the number of groups.
Silhouette: A score for how well a place fits the group it was assigned in a clustering. Higher values mean the place sits close to its own group and far from the others.
Principal components: A method that combines many correlated measures into a few summary scores, ordered by how much of the variation among places each captures. The first component is the single weighted combination that captures the most.
Ecological inference: Drawing conclusions about individuals from data about places or groups. A pattern across counties need not hold for the people inside them.

Methods

The typology groups tracts of the 50 states and DC by 7 ACS 2019-2023 measures of resources and settlement: log median household income, the poverty rate, the college share of adults, the single-parent share of households, the homeownership rate, the share aged 65 and over and log population density. No outcome and no race or ethnicity measure is an input. The eight outcomes and the Black and Hispanic shares are compared across the types, and the earlier fit on 13 inputs, which included four outcomes and the two race and ethnicity shares, is refit as a comparison. The clustering counts every tract once while type means are weighted by tract population, and the intervals come from a bootstrap over counties that conditions on the types and does not carry uncertainty about the typology.

Which tracts are in the typology

The typology covers the tracts of the 50 states and DC that have residents and all 7 inputs, are not institutional and have more than 200 residents. A tract is institutional when its SVI 2022 group-quarters share is 25 percent or more or it is one known chronic-care tract, the rule the book applies to USALEEP tracts; the flag is taken from SVI because USALEEP has rows only where a life expectancy exists. A typed tract need not have an outcome: each outcome is compared over the typed tracts that have it, and life expectancy exists for 77,763 of them. Puerto Rico is left out because the county map and the outcome measures cover the 50 states and DC.

Figure explained here: Figure 1

What the inputs measure and when

The inputs are log median household income, the poverty rate, the college share of adults 25 and over, the single-parent share of households, the homeownership rate and the share aged 65 and over (ACS 2019-2023), and the log of residents per square mile of land (ACS population, 2020 TIGER land area). Density and age describe settlement and are not outcomes; they are what separates these types from the four families of the deprivation-based clustering in Families of places, which uses the fifteen ADI measures.

The outcomes are life expectancy at birth (USALEEP, deaths 2010 to 2015), the adult income rank, teen births and incarceration of children from low-income families (Opportunity Atlas, children born 1978 to 1983, interpolated from 2010 to 2020 tracts by land area), and diabetes, smoking, frequent mental distress and obesity among adults (PLACES, modeled). The Black share (Black alone, Hispanic residents included), the Hispanic share and the ADI national rank are profile columns.

Figure explained here: Figure 2

How the types are numbered and named

Types are numbered by the population-weighted mean of the first principal component of the inputs, oriented to rise with log income, largest first, so the numbers do not depend on the initialization.

The names are the book's labels and are written in types_data.py, with an assertion that each profile fits its name. They describe income, poverty, education, family structure, tenure, age and density and name no race, ethnicity or outcome.

Figures explained here: Figure 2 and Figure 5

How a county gets a type

A county's type is the type that holds the most typed residents; a county has one when its typed tracts hold at least 50% of its residents, and a tie goes to the lower-numbered type. The count of types per county uses counties with at least 100 typed tracts and counts a type when it holds at least 10% of the typed residents.

Figure explained here: Figure 3

Weights and intervals

Type means are weighted by ACS 2019-2023 tract population, over the typed tracts that have the measure.

Intervals are 95% percentile intervals from 2,000 draws of whole counties with replacement (seed 12345), with Connecticut tracts assigned to the eight legacy counties; differences between two types and the shares of variance between types use the same draws. The intervals condition on the types and do not carry uncertainty about the typology.

The spread of life expectancy is the highest minus the lowest population-weighted group mean, and the R squared is the variance between groups over the total, both with the county bootstrap above.

Figure explained here: Figure 4

How the clustering was fitted and checked

The inputs are standardized with each tract counted once and clustered by k-means (scikit-learn, 8 groups, 20 starts, seed 12345, one thread). Eight groups is the book's choice, kept from the first edition, and the data do not select it. The fit weights every tract equally; a fit weighted by tract population agrees at 0.84.

Refits on 8 bootstrap resamples of tracts, assigned back to every tract by nearest centroid, agree with the typology at a median of 0.95 and at least 0.55.

The mean silhouette is computed on a random sample of 20,000 tracts (seed 12345) for the fit with 8 groups (20 starts) and for fits with 2 to 10 groups (10 starts each); it is highest at 2 groups. At each number of groups the same k-means is fit to a benchmark with no clusters, a multivariate normal with the correlations of the inputs and one draw per tract, scored on the same sample positions; the tracts score above the benchmark by at most 0.08. The 8-group benchmark with 20 starts gives 0.14. The simulated margins are symmetric and tract margins are not, so the benchmark is a guide.

The comparison refits the earlier k-means on its 13 inputs (the seven inputs, the Black and Hispanic shares, life expectancy, the adult income rank, diabetes and smoking; 8 groups, 20 starts, seed 12345, standardized over its own tracts) on the 77,745 typed tracts that have all of them, which are the tracts of the earlier typology. Its agreement with the typology, its spread of life expectancy and its R squared values are computed on those tracts, and so are the values for this chapter's types that are set beside them.

The principal-components figure shows a random sample of 6,000 typed tracts (seed 12345).

Figure explained here: Figure 5

What these data cannot show

References

Murray, Christopher J. L.; Kulkarni, Sandeep C.; Michaud, Catherine; Tomijima, Niels; Bulzacchelli, Maria T.; Iandiorio, Terrell J.; Ezzati, Majid (2006). Eight Americas: Investigating Mortality Disparities across Races, Counties, and Race-Counties in the United States. PLoS Medicine 3(9): e260. doi:10.1371/journal.pmed.0030260
Chetty, Raj; Hendren, Nathaniel (2018). The Impacts of Neighborhoods on Intergenerational Mobility I: Childhood Exposure Effects. The Quarterly Journal of Economics 133(3): 1107-1162. doi:10.1093/qje/qjy007

Provenance

Pipeline version: 0.1.0
Build script: book2/chapters/eight-types-of-neighborhood/build.py (sha256 0401bf488cb85b31eb791cd96bfa7c70d74e205cd1aea5763da3d96c8ab3a064)
Built on: 2026-10-28
Site commit: c2b1ff3309cb4a10833f884da91ac0057a66ad0a

Inputs

File	Size (bytes)	SHA-256, first 1 MB	SHA-256, last 1 MB
book2/chapters/eight-types-of-neighborhood/types_data.py	25,686	6d7e5d157e6c1d2a6ce404220d256e0bbd7dc6b8136bafdff53ceb0a07468122	6d7e5d157e6c1d2a6ce404220d256e0bbd7dc6b8136bafdff53ceb0a07468122
data/analytic/tract_atlas.parquet	39,659,925	29d5e4d943552d54aeb6ba92aadc939d9bd15bdea553c78357dbd516757be627	1e10d1ecf722340f23ee2212d4999a90250f85b65fa89b39e32db06d9472e22e
data/geo/tracts_2020.parquet	619,858,391	f4f05c8c7a63d1785ec2aad283de3f6fa839b6c437f13a1b96cea31d3344bf0f	7b3811247c6b3e322954f24a4a2384af52aef6ed8688f8dbdb0407d21ef80a59
data/staged/crosswalks/ct_tract2020_to_old_county.parquet	15,842	961ef39f31596ef65fca2c67d5f2f63e533c5dc9b49745d3bb6437844e4b831d	961ef39f31596ef65fca2c67d5f2f63e533c5dc9b49745d3bb6437844e4b831d
data/staged/svi/svi_tract2020_2022.parquet	17,740,415	cb3860d8edc2aaf1f2a02211a58f7a0b80457eb6ad9a37b5ec8abb2d5da9da10	e371a4a696d5bed05d54ad7c5b6ca2504508805b847ec415c2322be7f66ec2b2

Outputs

File	SHA-256
facts.json	9b5fa324c28f5faf9951ff17d7d2a7b52cc0f8db1da35566a157c0f14b5565f9
figures/modal_type_map.json	e7bf6b97530b641ddf30ea60305a69369d2b4ce25de0d2449b9ef08d03f1aa43
figures/pca_continuum.json	061b33a95bc751d1dbfdc8181fb4d4eb3edea046e4cd6e8104287a3fef7cf1c4
figures/sample_flow.json	0149d90223074f3db14f5b38f1f46a74ba476a066dd1617ff307173984c0f2c3
figures/type_outcomes.json	b01096122d02bb7d52d28939eda8ec2b8154a0a4b162f284033cb5c337bae210
figures/type_profiles.json	dbb555769ecef5f8a9d2d73d9a9615fa52fffdf60909ac3480f4a0803d2f92de
meta.json	8287fdd8357c1fca35bbcbe6612351bb4cda7451a13ef437ae1d950c34a91412
public/data/eight-types-of-neighborhood/modal_type_map.json	b433c7cd3f9a4c204d18126d8c943e69701be6e917e51ee96e1f9ec9813390b0
public/data/eight-types-of-neighborhood/pca_continuum.json	06c5add45f70ed23946415d3f1a277bf6cd241a750837c5360192e7dd0b36553
refs.json	0d466e104a404555a8699785fede9eb5fddf2508077d824b4daf5465aa7fde04

Machine formats

Report (Markdown): https://vishalsingh.org/zipcode/eight-types-of-neighborhood/report.md
Every estimate (JSON): https://vishalsingh.org/zipcode/report/eight-types-of-neighborhood/facts.json
Table 1, figure "sample_flow" (JSON): https://vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/sample_flow.json
Table 2, figure "type_profiles" (JSON): https://vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/type_profiles.json
Table 3, figure "modal_type_map" (JSON): https://vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/modal_type_map.json
Table 4, figure "type_outcomes" (JSON): https://vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/type_outcomes.json
Table 5, figure "pca_continuum" (JSON): https://vishalsingh.org/zipcode/report/eight-types-of-neighborhood/figures/pca_continuum.json
Payload of "modal_type_map" (JSON): https://vishalsingh.org/zipcode/data/eight-types-of-neighborhood/modal_type_map.json
Payload of "pca_continuum" (JSON): https://vishalsingh.org/zipcode/data/eight-types-of-neighborhood/pca_continuum.json
Index of every report: https://vishalsingh.org/zipcode/llms.txt; all reports in one file: https://vishalsingh.org/zipcode/llms-full.txt