Mariyana Zapryanova Seminar

Department of Resource Economics Fall 2026 Seminar Series

Mariyana Zapryanova, Smith College

Title: Liquid Assets: Plasma Donation Income and Crime

Abstract: Paid plasma donation functions as an income-earning opportunity in the US, with access conditioned on passing drug-use screenings, so the arrival of blood plasma center represents a contingent but meaningful income shock for would-be donors. Using detailed data on the location of blood plasma centers and three complementary difference-in-differences research designs, we study the impact of these centers on crime outcomes. Our findings indicate that the opening of a plasma center in a city leads to a 12% drop in the crime rate, an effect driven primarily by property and drug-related offenses. A within-city design confirms these findings, highlighting large crime drops in neighborhoods close to a newly opened plasma center. We also document declines in recidivism among individuals released into areas with newly opened plasma centers, showing that the effects extend across multiple margins of criminal behavior. To probe the underlying mechanisms, we conduct additional analyses that examine heterogeneity across sociodemographic groups, offender age profiles, and incapacitation using center-level opening times. We find strong support in favor of a financial channel, which operates most strongly in less affluent areas and among younger age groups. We find no support for the idea that incapacitation drives our results.