Selective Verification in Centralized Admissions: Which Priority Claims Must Be Checked?

Abstract

Centralized admissions platforms grant priority based on self-reported facts such as residence, sibling status, or family income, and a false claim can cost another applicant her seat. Verifying every claim before matching is expensive, yet checking only admitted applicants afterward is unsafe: a false claim by an applicant who ends up unmatched may already have triggered a chain of rejections. We show how a platform can check far fewer claims without changing any outcome. A claim matters only if it can move its applicant across a school's admission cutoff, and we give an exact, easily computed test for when this happens. Checking only such claims, and only when they could change a school's tentative choice, reproduces every application, rejection, and assignment of deferred acceptance under full verification. When claims are truthful, checking the highest claimed priority first minimizes checks among such policies at each school decision, and the number of checks never exceeds the school's capacity. Truthful reporting of preferences and eligibility is a weakly dominant strategy, so incentives deliver the conditions under which this audit order is optimal. In simulated markets, the policy cuts verification by 76 percent relative to checking every claim upfront and by 36 percent relative to checking each claim when it first reaches a school. The design principle is to verify decisions, not files.