Abstract: While primarily publicly funded government entities, most public school districts receive private donations. I estimate how local school taxes crowd out private, voluntary contributions to public education. To do this, I exploit quasi-experimental variation in tax revenue stemming from local elections. I collect data from a large set of referenda in which local taxes face voter approval in four Midwestern states, combined with administrative records of the sources of school district revenues. Using a regression discontinuity design around voting thresholds that determine passage of local referenda, I show that private contributions to public school systems are not crowded out by local taxes. I can reject that a one dollar increase in taxes causes more than approximately a 1.5 cent decrease in private contributions.