{
  "alt": "Dot plot with one row per estimate of the change in the income gap and a confidence interval on each, with a line at zero. All six dots lie to the right of zero. The five comparisons of two income groups lie between {fact:did_wide} and {fact:did_real} points. The two-bracket estimate is the smallest, the unweighted estimate the next smallest, the constant-real-dollar estimate the largest, and the rank slope, on a different scale and drawn in a different colour, is {fact:did_rank}.",
  "caption": "All six estimates are above zero. The five comparisons of two income groups range from {fact:did_wide} to {fact:did_real} points, and the rank slope, on a different scale, is {fact:did_rank}. The rows differ in how the income groups are defined, as the notes below explain. Whiskers are confidence intervals.",
  "data": [
    {
      "conf_high": 18.85,
      "conf_low": 10.7926,
      "definition": "Main: highest vs lowest",
      "estimate": 14.8213,
      "group": "Two income groups",
      "n": 17815
    },
    {
      "conf_high": 14.2692,
      "conf_low": 8.45442,
      "definition": "Unweighted",
      "estimate": 11.3618,
      "group": "Two income groups",
      "n": 17815
    },
    {
      "conf_high": 12.4258,
      "conf_low": 7.92847,
      "definition": "Top 2 vs bottom 2",
      "estimate": 10.1772,
      "group": "Two income groups",
      "n": 44897
    },
    {
      "conf_high": 19.9956,
      "conf_low": 12.5695,
      "definition": "Top group, fixed share",
      "estimate": 16.2826,
      "group": "Two income groups",
      "n": 19225
    },
    {
      "conf_high": 24.8198,
      "conf_low": 16.3733,
      "definition": "Real-dollar cutoffs",
      "estimate": 20.5965,
      "group": "Two income groups",
      "n": 18933
    },
    {
      "conf_high": 22.5596,
      "conf_low": 15.2771,
      "definition": "Rank slope (other scale)",
      "estimate": 18.9183,
      "group": "Different scale",
      "n": 60804
    }
  ],
  "id": "gap_definitions",
  "notes": [
    "Each row is a difference in differences, the change in the gap between two elections, estimated by weighted least squares with standard errors clustered by state (the states and the District of Columbia).",
    "Unweighted: the same estimate without the survey weights. Top 2 vs bottom 2: each group is two brackets.",
    "Top group, fixed share: in each election the top group's income cutoff is set so that the group holds about the same share of voters as the highest bracket does in 2024; the comparison group is the lowest bracket.",
    "Real-dollar cutoffs: both cutoffs are held constant in real dollars with the consumer price index, at the income band edges nearest the 2024 cutoffs deflated to each election.",
    "Rank slope: the vote is regressed on each voter's income rank within the election, so no dollar cutoffs are used. The estimate is the change in the difference between the lowest and the highest rank, and it does not compare two groups of voters."
  ],
  "source": "Cooperative Election Study cumulative file, presidential years 2008, 2012, 2016, 2020 and 2024; weighted (weight_cumulative); two-party presidential voters who reported household income",
  "spec": {
    "colors": {
      "Different scale": "muted",
      "Two income groups": "cat1"
    },
    "group": "group",
    "hi": "conf_high",
    "lo": "conf_low",
    "n": "n",
    "reference": 0,
    "sort": "data",
    "x": "estimate",
    "xDomain": [
      0,
      26
    ],
    "xFormat": {
      "digits": 0
    },
    "xLabel": "Change in the gap, 2008 to 2024 (percentage points)",
    "y": "definition"
  },
  "subtitle": "Change from 2008 to 2024 in the Democratic share of the higher-income group minus that of the lower-income group, percentage points; two-party voters who reported income; 95% intervals clustered by state",
  "table": {
    "columns": [
      {
        "key": "definition",
        "label": "Estimate"
      },
      {
        "format": {
          "digits": 1,
          "signed": true
        },
        "key": "estimate",
        "label": "Change (points)"
      },
      {
        "format": {
          "digits": 1
        },
        "key": "conf_low",
        "label": "95% CI low"
      },
      {
        "format": {
          "digits": 1
        },
        "key": "conf_high",
        "label": "95% CI high"
      },
      {
        "key": "n",
        "label": "n observations"
      }
    ]
  },
  "title": "The gap between higher and lower incomes rose under all six definitions, by {fact:did_wide} to {fact:did_real} points in the five comparisons of two groups",
  "type": "dot",
  "width": "wide"
}