Finding 6 — State policy as the lever

Youth turnout rises with the count of facilitative election-administration policies a state has in effect — automatic voter registration, same-day registration, online voter registration, pre-registration at 16 or 17, no-excuse absentee voting, universal vote-by-mail. The correlation is strongest in the cells where the access barriers in Finding 3 concentrate. For same-day registration and mail-ballot expansion, the peer-reviewed literature supports causal attribution and we cite those effects directly; elsewhere we report the correlation and leave causal interpretation open.

Policy score × youth turnout (2020 + 2022 + 2024 pooled)

The policy score sums six NCSL-sourced flags: AVR, SDR, OVR, pre-registration at 16/17, no-excuse absentee, universal VBM. Values range from 0 (no policies) to 6 (all policies).

Each point is one state-year. Fitted line is an ordinary-least-squares regression; the slope estimates the average change in youth turnout associated with a one-unit change in policy score, holding nothing else constant. Source: state_year_panel (CPS calibrated + NCSL policies).

Policy score × youth-senior gap

The same relationship viewed through the gap lens. States with higher policy scores tend to show smaller senior-youth gaps.

Literature-supported causal effects

For two policies the peer-reviewed literature supports direct causal attribution for youth turnout effects, beyond the correlational view above:

Same-day registration. Peer-reviewed estimates put the youth-specific effect in the range of +2 to +5 percentage points (Gerber & Green 2019, synthesizing multiple studies). This is one of the largest single-policy effects documented for the 18-29 cohort.
Mail-ballot expansion / universal VBM. Peer-reviewed estimates place the turnout effect in the range of +2 to +5 percentage points, with stronger effects for low-propensity voters (Gerber & Green 2019; Gronke et al. at Reed EVIC). Youth effects are at the upper end of this range.

For the remaining four policies (AVR, OVR, pre-registration, no-excuse absentee), the causal literature is moderate-to-strong in support of an effect but less precisely estimated for the youth sub-cohort specifically. The correlational finding above is consistent with the literature but should not be read as establishing causation state-by-state.

What this page establishes

Higher state policy scores correlate with higher youth turnout in the 2020-2024 state-year panel.
The policy effect is youth-asymmetric. State policy variation explains more variance in youth turnout than in overall turnout.
Causal evidence concentrates on two levers — same-day registration and mail-ballot expansion — where the peer-reviewed youth effect range is +2 to +5 pp per policy.
Correlation is not uniform across cells. States where the policy-score lift is largest are those with the highest access-barrier responses among non-registrants (see Finding 3 cross-cut).

Cross-references

Finding 3 — Who didn't register, and why — the access-barrier diagnostic these policies address
Finding 5 — Method preference — revealed method use by state regime
Recommendations — cost-per-marginal-voter ranges for each policy

So what

For Secretaries of State. Your state's current policy score sits on the scatterplot above. A one-unit move up the policy score is associated with an average youth-turnout change consistent with the literature ranges. State-Gap Explorer and Finding 3 let you identify which specific barrier is most cited by your state's non-registrants, directing attention to the policy that addresses that barrier.

For foundation officers. Policy-reform grantmaking sits at the $0-$5 per-marginal-voter end of the ROI catalog — dramatically lower than programmatic GOTV — because the per-cycle cost amortizes once the policy is in force. The evidence strongest for same-day registration and mail-ballot expansion.

For the public. Where you live meaningfully shapes how much time, paperwork, and pre-planning it takes to register and vote. State policy variation is not about candidate preference; it is about the operational cost of participation.

Methodology. Policy score from NCSL as of 2026-04; effective dates backfilled from state statute citations (see data/external/ncsl_laws/). State-year panel combines CPS-calibrated turnout rates (Census P20 methodology), McDonald VEP benchmarks, and NCSL policy flags. Correlational findings are state-year level; individual-level causal claims require within-state pre/post designs or the peer-reviewed literature cited above. Full provenance: methodology page.