Democratic mayors have no effect on crime, but do reduce the Black share of arrests for petty crimes

We examine whether mayors’ partisan affiliations lead to differences in crime rates, arrest rates, and the racial composition of arrests. We employ a regression discontinuity design centered around close mayoral elections to determine the causal effect of electing a Democratic rather than Republican mayor on policing and crime outcomes in medium and large US cities. Mayoral partisanship does not affect overall crime rates, arrests, or police employment and expenditures. However, it does influence the racial distribution of arrests. The election of a Democratic mayor decreases the Black share of arrests by a modest amount. This effect is driven by decreases in arrests of Black individuals for both “drug crimes” and “other crimes.” This may be tied to police staffing choices, as electing a Democratic mayor also affects police officer demographics: electing a Democratic mayor increases the Black share of police officers. These results reaffirm the importance of politics in policing.