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Results

PolicyEngine

Multi-Variable Validation: 14-Year Forecasting Horizon

We tested value forecasting across 17 GSS variables using gpt-3.5-turbo-instruct (September 2021 training cutoff) to predict 2024 values from a 2010 baseline—a 14-year forecasting horizon.

Table 1:Multi-Variable Forecasting Results (2010→2024, all 16 variables tested)

Variable20102024 ActualPredictedErrorDir
PRAYER44%46%46%0
FEPOL79%82%81%-1
NATEDUC72%76%75%-1
GUNLAW74%70%72%+2
POLVIEWS29%29%31%+2
NATENVIR57%66%60%-6
NATHEAL60%74%80%+6
TRUST33%25%31%+6
FAIR38%46%40%-6
GRASS48%68%60%-8
PREMARSX53%65%56%-9
EQWLTH42%54%45%-9
HELPPOOR28%39%30%-9
CAPPUN32%40%30%-10
ABANY44%60%46%-14
NATRACE34%51%37%-14

Key findings across 16 variables:

The model correctly captured the direction of change in nearly all cases, including the decline in social trust (TRUST: 33%→25%) and stability in gun permit support (GUNLAW: 74%→70%). The largest errors occurred on variables with rapid change (NATRACE, ABANY) where the model under-predicted the magnitude.

Clean Test: GPT-4o Predicting GSS 2024

For a methodologically rigorous test, we used GPT-4o (training cutoff October 2023) to predict GSS 2024 data (collected April-December 2024). This ensures the model could not have seen the target values.

Table 2:GPT-4o Predictions vs. GSS 2024 Actual

VariablePrediction90% CIActualError
HOMOSEX69%[66, 72]54.7%+14.3%
GRASS73%[70, 76]68.5%+4.5%

The model missed a major reversal. HOMOSEX (acceptance of same-sex relationships) had increased steadily for decades: 13% (1990) → 27% (2000) → 42% (2010) → 62% (2021). GPT-4o extrapolated this trend, predicting 69% for 2024.

Instead, the actual value was 54.7%—a 7 percentage point drop from 2021 and the first reversal in over 30 years.

Multi-Variable Analysis

The reversal was not isolated. We analyzed six GSS variables:

Table 3:GSS 2024 Results Across Variables

Variable2018202120222024Pattern
HOMOSEX57%62%61%55%↓ Reversal
PREMARSX62%66%69%65%↓ Peaked
NATRACE56%52%56%51%↓ Declining
ABANY50%56%59%60%↑ Rising
GUNLAW72%67%71%70%→ Stable
CAPPUN37%44%40%40%→ Stable

Values did not move in lockstep. While ABANY (abortion) continued rising post-Dobbs, HOMOSEX and NATRACE (spending on racial issues) reversed. This divergence would be missed by any model assuming “liberalization” as a general pattern.

Demographic Decomposition

We analyzed HOMOSEX by party identification:

Table 4:HOMOSEX by Party (% “Not Wrong at All”)

YearDemocratIndependentRepublican
201862%63%45%
202176%59%43%
202471%57%36%
Change 2021→24-5-2-7

The reversal occurred across all party groups but was largest among Republicans (-7 points). This is consistent with backlash dynamics triggered by political mobilization.

By age group:

Table 5:HOMOSEX by Age (% “Not Wrong at All”)

Year18-2930-4445-6465+
202179%68%61%53%
202469%61%51%45%
Change-10-7-10-8

The largest drops were among the youngest (18-29) and middle-aged (45-64) groups. This contradicts simple generational replacement models where younger cohorts drive liberalization.

Long-Term Forecasts with Calibrated Uncertainty

We generated long-term forecasts using quantile elicitation and EMOS-style calibration gneiting2005calibrated. For each variable, we elicited five quantiles (10th, 25th, 50th, 75th, 90th percentiles) and calibrated the uncertainty by optimizing CRPS on the 2024 holdout data.

Calibration Results (17 variables, 2021→2024):

Table 6:Calibrated Long-Term Forecasts (GPT-4o)

Variable2024 Actual203020502100
HOMOSEX55%66% [57,75]75% [64,86]80% [69,91]
GRASS68%72% [57,87]80% [57,103]80% [57,103]
PREMARSX65%70% [59,81]80% [69,91]80% [69,91]
ABANY60%60% [51,69]60% [42,78]60% [37,83]
CAPPUN40%42% [33,51]45% [34,56]55% [32,78]
TRUST25%28% [21,35]27% [18,36]27% [18,36]
POLVIEWS29%30% [25,35]30% [23,37]31% [24,38]

Brackets show calibrated 80% confidence intervals.

Key observations:

These forecasts should be treated as registered predictions subject to future validation, not reliable projections. The 2024 calibration shows models are overconfident; longer horizons likely involve even greater uncertainty than shown.

Income-Values Relationship

We found a strong gradient between income and values in GSS 2024:

Table 7:HOMOSEX by Income Quartile (2024)

Income Quartile% AcceptMedian Income
Q1 (lowest)43%$7,700
Q254%$31,000
Q361%$56,000
Q4 (highest)67%$139,000

This 24-point gap suggests economic conditions may influence values. Under AI-driven growth scenarios, rising incomes could shift values—though the direction and causality are uncertain.