{
  "alt": "Dot chart of three slopes in points per decade with confidence intervals and a reference line at zero. Over the whole period the other-party slope is {fact:slope_oth}, the own-party slope is {fact:slope_own} and the gap slope is {fact:slope_gap}. A second view splits the record at 1990: after 1990 the other-party slope is {fact:slope_oth_post}, and the other-party slope before 1990 and both own-party slopes within periods have intervals that include zero.",
  "caption": "The other-party slope is more negative than the own-party slope, and both intervals lie below zero. Each dot is the slope of a line fitted to respondents' ratings on survey year, with each respondent counted by survey weight, and a confidence interval from standard errors clustered on survey year.",
  "data": [
    {
      "conf_high": -0.0854638,
      "conf_low": -1.3696,
      "estimate": -0.727533,
      "n": 43063,
      "period": "Own party",
      "waves": 18,
      "window": "Whole record"
    },
    {
      "conf_high": -5.90195,
      "conf_low": -7.94437,
      "estimate": -6.92316,
      "n": 43063,
      "period": "Other party",
      "waves": 18,
      "window": "Whole record"
    },
    {
      "conf_high": 7.57414,
      "conf_low": 4.81711,
      "estimate": 6.19563,
      "n": 43063,
      "period": "Gap, own minus other",
      "waves": 18,
      "window": "Whole record"
    },
    {
      "conf_high": 7.14408,
      "conf_low": -3.9821,
      "estimate": 1.58099,
      "n": 11264,
      "period": "Own party, 1978 to 1990",
      "waves": 7,
      "window": "Split at 1990"
    },
    {
      "conf_high": 0.465717,
      "conf_low": -0.829986,
      "estimate": -0.182134,
      "n": 33455,
      "period": "Own party, 1990 to 2024",
      "waves": 12,
      "window": "Split at 1990"
    },
    {
      "conf_high": 1.73224,
      "conf_low": -3.33864,
      "estimate": -0.8032,
      "n": 11264,
      "period": "Other party, 1978 to 1990",
      "waves": 7,
      "window": "Split at 1990"
    },
    {
      "conf_high": -6.78206,
      "conf_low": -9.66041,
      "estimate": -8.22123,
      "n": 33455,
      "period": "Other party, 1990 to 2024",
      "waves": 12,
      "window": "Split at 1990"
    }
  ],
  "id": "slopes",
  "notes": [
    "Intervals come from a t distribution, which is wider than the normal curve when there are few surveys, with one fewer degree of freedom than the number of surveys."
  ],
  "source": "ANES Cumulative Data File, 1978-2024; partisans including leaners; weighted (VCF0009z)",
  "spec": {
    "hi": "conf_high",
    "lo": "conf_low",
    "n": "n",
    "reference": 0,
    "sort": "data",
    "x": "estimate",
    "xDomain": [
      -12,
      9
    ],
    "xFormat": {
      "digits": 1
    },
    "xLabel": "Change in the mean rating per decade (points)",
    "y": "period"
  },
  "subtitle": "Slope of the mean thermometer rating on survey year, points per decade, partisans including leaners, 1978 to 2024",
  "title": "The other-party rating changed by {fact:slope_oth} points per decade and the own-party rating by {fact:slope_own}",
  "type": "dot",
  "views": [
    {
      "filter": {
        "window": "Whole record"
      },
      "id": "whole",
      "label": "Whole record"
    },
    {
      "caption": "The intervals for both own-party slopes and for the other-party slope before 1990 include zero. The split year was chosen after looking at the series, the windows before 1990 rest on seven surveys, and the other-party slope before 1990 is {fact:slope_oth_pre88} for 1978 to 1988 and {fact:slope_oth_pre96} for 1978 to 1996.",
      "filter": {
        "window": "Split at 1990"
      },
      "id": "split",
      "label": "Split at 1990",
      "title": "Split at 1990, the other-party slope is {fact:slope_oth_pre} before 1990 and {fact:slope_oth_post} after, and the own-party slopes are {fact:slope_own_pre} and {fact:slope_own_post}"
    }
  ],
  "width": "body"
}