{
  "alt": "Map of Cook County census tracts. In the denial-rate view tracts are shaded from low to high by the denied share of home-purchase applications, with gray tracts that have too few applications. In the grade view the tracts covered by the Chicago HOLC map are colored by grade A to D and the rest are gray.",
  "caption": "The first view shades each tract by its denial rate; gray tracts have no rate, and the tooltip says why. The second view colors each tract by its 1930s grade, with gray for tracts that graded polygons cover less than halfway, which include parts of the county that the Chicago map did not reach. Comparing graded with ungraded tracts is not comparing grade D with grade A, and grade A rests on {fact:cook_tracts_a} tracts.",
  "data": [],
  "id": "cook_denial_map",
  "notes": [
    "{fact:cook_n_shaded} of the {fact:cook_n_tracts} tracts have a rate and {fact:cook_n_gray} do not, because the tract has fewer than {fact:cook_floor} decided applications, fewer than {fact:suppress_floor} applications in all (withheld), or no row in the file. {fact:cook_n_graded} tracts have a grade, all of them in Chicago. The rate in the tooltip carries a 95% interval from the Wilson formula, which treats applications as independent, so it is narrower than a bootstrap over tracts would give.",
    "The share graded in the top fifth minus the share in the bottom fifth is {fact:cook_graded_diff} percentage points, with an interval from a bootstrap over tracts that includes zero. Pooled over the shaded tracts, the denial rate is {fact:cook_rate_a} in grade A tracts, {fact:cook_rate_b} in B, {fact:cook_rate_c} in C, {fact:cook_rate_d} in D and {fact:cook_rate_none} in tracts with no grade, with intervals from a bootstrap over tracts."
  ],
  "source": "HMDA Loan/Application Register, 2024, tract totals of decided applications; Mapping Inequality HOLC maps (1935-1940) overlaid on 2020 tracts; full counts, pooled rates",
  "spec": {
    "geoid": "geoid",
    "legendLabel": "Denied share of decided home-purchase applications, 2024 (%)",
    "payload": "cook_denial_map.json",
    "region": "cook",
    "scale": {
      "palette": "seq",
      "thresholds": [
        5,
        10,
        15,
        20,
        30
      ],
      "type": "threshold"
    },
    "tooltipKeys": [
      "decided",
      "holc",
      "adi"
    ],
    "tooltipLabels": {
      "adi": "Deprivation rank (1 least, 100 most deprived)",
      "decided": "Decided applications",
      "holc": "HOLC grade, 1930s"
    },
    "value": "rate",
    "valueFormat": {
      "digits": 1
    }
  },
  "subtitle": "Denied share of decided home-purchase applications, 2024, in Cook County tracts with at least {fact:cook_floor} decided applications, and the HOLC grade covering most of each tract",
  "title": "In Cook County, {fact:cook_top_graded} of the tracts in the top fifth of denial rates and {fact:cook_bottom_graded} of those in the bottom fifth lie in the part of the county that the 1930s map graded, a difference these data cannot tell from zero",
  "type": "tract-map",
  "views": [
    {
      "id": "rate",
      "label": "Denial rate"
    },
    {
      "caption": "Tracts are colored by the grade that covers most of their area; gray tracts are covered less than halfway by graded polygons. Compare with the denial-rate view.",
      "id": "grade",
      "label": "1930s HOLC grade",
      "spec": {
        "legendLabel": "HOLC grade covering most of the tract",
        "scale": {
          "categories": [
            {
              "color": "holcA",
              "label": "Grade A (labeled best)",
              "value": "A"
            },
            {
              "color": "holcB",
              "label": "Grade B",
              "value": "B"
            },
            {
              "color": "holcC",
              "label": "Grade C",
              "value": "C"
            },
            {
              "color": "holcD",
              "label": "Grade D (labeled hazardous)",
              "value": "D"
            }
          ],
          "type": "categorical"
        },
        "value": "holc"
      },
      "title": "Chicago's 1930s HOLC grades cover {fact:cook_n_graded} Cook County tracts"
    }
  ],
  "width": "full"
}