Finding 3 — Who didn't register, and why

Before "why didn't they vote?" comes a more basic question: who never made it onto the rolls? When the Census asks young non-registrants directly, the leading answers are access barriers — missed deadlines, didn't know how, recent moves. Engagement reasons (not interested, vote wouldn't matter) come in smaller than the apathy narrative assumes. The registration layer is where policy reform has the cleanest evidence.

What non-registrants say

CPS VOYNOTREG asks respondents who are not registered to select the reason. We harmonize the codes into five policy-relevant categories:

access — missed deadlines, didn't know how, recent move (addressable by AVR, SDR, OVR, pre-registration)
engagement — not interested, vote wouldn't matter (addressable by civic infrastructure, outreach)
personal — illness, language barrier, ineligible (addressable by targeted accommodations)
other — miscellaneous / don't know

Pooled across 2000-2024, 18-29 non-registrants. The access category dominates across the pooled series, with engagement as the secondary cluster.

By race × gender (pooled 2000-2024)

Pooled 2000-2024 non-registrant responses by race × gender. Cells with unweighted n under 400 are published as indicative. Share percentages sum to 100% within each cell; "other" residuals absorb don't-knows and miscellaneous codes.

What the cell view shows

Access barriers × state policy availability

A non-registrant citing "missed the deadline" in a state with same-day registration is a different problem from the same response in a state without it. The Finding 6 — Policy lever page maps non-registrant shares against state NCSL policy availability directly. The headline: access-category responses are consistently higher in states that lack same-day registration or online voter registration at the time of the cycle.

So what

For Secretaries of State. The top barrier cited by non-registrants in your state is, with high probability, operational — deadlines, knowledge gaps, and residence churn. This is your domain. Finding 6 pairs these responses with state NCSL policy flags; Recommendations lists the policy levers with evidence-backed effect ranges.

For foundation officers. Access-category non-registrants are the cheapest marginal voters in the intervention catalog — policy reform amortizes to $0-$5 per marginal voter; OVR portals to $5-$15. Compare to programmatic GOTV at $20-$500. The reason diagnostic validates that weighting.

For the public. Non-voting among young adults is not, in its plurality, a story about not caring. It is, in the first layer, a story about never reaching the rolls.

Methodology. VOYNOTREG harmonization maps the raw IPUMS codes to policy-relevant categories per scripts/process_cps.py. Pooled weighted shares use VOSUPPWT. The universe is citizens 18-29 who are not registered AND who provided a VOYNOTREG answer (i.e., excludes "NIU: registered" and "Refused / Don't know"). Unweighted cell n reflects the denominator for the suppression rule. Full provenance: methodology page.