{
  "title": "AAPOR expanded election-polling evidence",
  "checked_date": "2026-10-31",
  "source": {
    "name": "AAPOR Task Force on 2024 Pre-Election Polling",
    "url": "https://aapor.org/wp-content/uploads/2025/10/AAPOR-Task-Force-on-2024-Pre-Election-Polling_Report.pdf",
    "publication_date": "2025-10-29",
    "publication_announcement": "https://aapor.org/announcements/2024-pre-election-polling-report/",
    "replication_code": "https://github.com/umisrcps/aapor_preelection_2024"
  },
  "method": {
    "units": "percentage points",
    "margin": "published Democratic percentage minus published Republican percentage; no D+R renormalization",
    "signed_error": "poll D-R margin minus recorded election D-R margin",
    "positive_signed_error": "Democratic margin overstated",
    "negative_signed_error": "Republican margin overstated",
    "mae": "analytic-weighted mean of individual absolute margin errors",
    "window": "final fieldwork date 0 through 13 days before or on Election Day",
    "window_2024": {"first_date": "2024-10-23", "last_date": "2024-11-05"},
    "weighting": "AAPOR duplicate/reposting and overlapping tracking-poll adjustments; not population-weighted or equal-state averages",
    "counts_unit": "published survey-contest matchups; one survey can cover several contests",
    "historical_comparability": "Use the revised 2024-report series together; do not splice in headline numbers from earlier AAPOR reports."
  },
  "presidential_history": {
    "source_table": "Table 2.2.1, printed page 17",
    "rows": [
      {"year": 2000, "national_mae": 3.9, "national_signed": -3.3, "state_mae": 4.7, "state_signed": -1.7},
      {"year": 2004, "national_mae": 2.3, "national_signed": 1.4, "state_mae": 3.3, "state_signed": 1.1},
      {"year": 2008, "national_mae": 2.2, "national_signed": -0.1, "state_mae": 3.5, "state_signed": 0.2},
      {"year": 2012, "national_mae": 3.1, "national_signed": -3.0, "state_mae": 3.2, "state_signed": -1.9},
      {"year": 2016, "national_mae": 2.1, "national_signed": 1.0, "state_mae": 5.7, "state_signed": 3.3},
      {"year": 2020, "national_mae": 4.1, "national_signed": 3.7, "state_mae": 4.8, "state_signed": 4.0},
      {"year": 2024, "national_mae": 2.6, "national_signed": 2.5, "state_mae": 3.0, "state_signed": 2.6}
    ]
  },
  "office_snapshot_2024": {
    "source_table": "Table 2.1.1, printed pages 12-13",
    "unique_surveys_all_offices": 403,
    "rows": [
      {"id": "presidential_national", "label": "President: national popular vote", "matchups": 60, "firms": 36, "contests": 1, "mae": 2.6, "signed": 2.5},
      {"id": "presidential_state", "label": "President: all covered states", "matchups": 291, "firms": 62, "contests": 35, "mae": 3.0, "signed": 2.6},
      {"id": "presidential_swing_state", "label": "President: seven swing states", "matchups": 190, "firms": 44, "contests": 7, "mae": 2.3, "signed": 2.0, "states": ["Arizona", "Georgia", "Michigan", "Nevada", "North Carolina", "Pennsylvania", "Wisconsin"]},
      {"id": "presidential_other_state", "label": "President: other covered states", "matchups": 101, "firms": 38, "contests": 28, "mae": 4.3, "signed": 3.6},
      {"id": "senate", "label": "U.S. Senate", "matchups": 197, "firms": 54, "contests": 27, "mae": 3.3, "signed": 2.4},
      {"id": "governor", "label": "Governor", "matchups": 27, "firms": 17, "contests": 7, "mae": 5.0, "signed": 3.8},
      {"id": "house_district", "label": "U.S. House: individual districts", "matchups": 28, "firms": 11, "contests": 20, "mae": 7.0, "signed": 4.9},
      {"id": "presidential_congressional_district", "label": "President: congressional-district electoral votes", "matchups": 8, "firms": 4, "contests": 5, "mae": 4.7, "signed": 4.5, "source_label": "Other presidential"},
      {"id": "all_contests", "label": "All evaluated contests", "matchups": 611, "firms": 86, "contests": 95, "mae": 3.3, "signed": 2.7}
    ],
    "warning": "Swing-state and other-state rows partition the all-state row; do not sum them again when counting all offices. House district polls are not generic congressional-ballot polls."
  },
  "selected_nonpresidential_comparisons": [
    {"year": 2020, "id": "senate", "mae": 6.0, "signed": null, "matchups": null, "source_location": "Section 2.2, printed page 19"},
    {"year": 2020, "id": "governor", "mae": 7.3, "signed": null, "matchups": null, "source_location": "Section 2.2, printed page 19"},
    {"year": 2020, "id": "house_district", "mae": 7.1, "signed": null, "matchups": null, "source_location": "Section 2.2, printed page 19"},
    {"year": 2022, "id": "senate", "mae": 4.8, "signed": -1.2, "matchups": 150, "source_location": "Appendix I.3, printed page 72"}
  ],
  "all_office_comparisons": [
    {"year": 2016, "mae": 5.2, "signed": 3.1, "source_location": "Section 2.1, printed pages 12,15"},
    {"year": 2020, "mae": 5.3, "signed": 4.6, "source_location": "Section 2.1, printed pages 12,15"},
    {"year": 2024, "mae": 3.3, "signed": 2.7, "source_location": "Table 2.1.1"}
  ],
  "coverage_matrix": [
    {"category": "President: national", "included": true, "harmonized_aapor": "2000-2024, seven presidential cycles", "separate_archive_analysis": "2000-2020", "historical_context": "Gallup final estimates 1936-2012 are one-firm context, not an all-pollster historical series", "limitation": "National popular vote, not Electoral College winner"},
    {"category": "President: state", "included": true, "harmonized_aapor": "2000-2024, seven presidential cycles", "separate_archive_analysis": "2000-2020", "limitation": "Only states with eligible published polls; 35 states in the 2024 final window"},
    {"category": "President: Maine/Nebraska congressional districts", "included": true, "harmonized_aapor": "2024 snapshot only in this extracted dataset", "separate_archive_analysis": "Must remain distinct from U.S. House races", "limitation": "Five covered electoral-vote district contests, eight matchups"},
    {"category": "U.S. Senate", "included": true, "harmonized_aapor": "2024 snapshot plus selected 2020/2022 comparisons", "separate_archive_analysis": "1998-2022, separately labeled original calculation", "limitation": "Different states/races are up each cycle; polls concentrate in selected contests"},
    {"category": "U.S. House: national generic congressional ballot", "included": true, "harmonized_aapor": null, "separate_archive_analysis": "1998-2022, separately labeled original calculation", "historical_context": "Primary research documents generic-ballot series back to 1946; older Gallup/Pew summaries use different periods and vote-share metrics", "limitation": "Benchmark national House vote, not seat count, chamber control, or an individual district"},
    {"category": "U.S. House: individual district polls", "included": true, "harmonized_aapor": "2024 snapshot plus 2020 MAE comparison", "separate_archive_analysis": "1998-2022, separately labeled original calculation", "limitation": "Not a representative sample of all 435 districts; 20 covered contests in the 2024 final window"},
    {"category": "Governor", "included": true, "harmonized_aapor": "2024 snapshot plus 2020 MAE comparison", "separate_archive_analysis": "1998-2022, separately labeled original calculation", "limitation": "Uneven cycle coverage; seven covered contests in the 2024 final window"},
    {"category": "Presidential/congressional primaries and caucuses", "included": false, "harmonized_aapor": null, "limitation": "Excluded from these general-election series; multicandidate and turnout rules require separate evaluation"},
    {"category": "Special elections and runoffs", "included": false, "harmonized_aapor": null, "limitation": "Outside the AAPOR 2024 general-election evaluation frame; any case study must be clearly separated"},
    {"category": "State legislatures and other statewide offices", "included": false, "harmonized_aapor": null, "limitation": "No harmonized outcome-linked dataset verified for this report"},
    {"category": "Local elections and ballot measures", "included": false, "harmonized_aapor": null, "limitation": "No harmonized outcome-linked dataset verified for this report"},
    {"category": "Approval, issue, and public-opinion polling", "included": false, "harmonized_aapor": null, "limitation": "Office election outcomes are not a direct accuracy benchmark for these questions"},
    {"category": "2026 general election", "included": false, "harmonized_aapor": null, "limitation": "Outcome pending as of 2026-10-31; Election Day is 2026-11-03"}
  ],
  "extraction_cautions": [
    "Figure 2.2.1 plots Senate/Governor/House histories for 2006-2024 but the report does not publish complete exact numeric tables for those histories. No graph-digitized approximations are represented as exact values here.",
    "The public replication repository lists scripts but not the primarydataset.rdata loaded by the principal analysis; the AAPOR series was transcribed, not independently recalculated.",
    "Appendix I.1 reports non-swing-state presidential MAE 4.2 while main Table 2.1.1 says 4.3. This extraction uses the main table.",
    "RMSE and median values differ between Appendices H.2 and I.1. Those inconsistent additional statistics are deliberately not included.",
    "Do not merge AAPOR analytic-weighted final-fieldwork statistics with original archive latest-per-firm or midpoint-based calculations into one supposedly consistent line."
  ]
}