This is joint work with the blueskyless Edoardo Teso and Rui Yu. The full paper is here: static1.squarespace.com/static/5c819...

Our findings are consistent with a significant influence of public sector unions in local politics. We are excited for the new avenues for research on local interest groups that our new dataset will facilitate!

Leveraging a within-city design, we show that the election of a police union–backed mayor leads to 1) an increase in the size of the police department; but 2) no improvement in police performance (if anything, performance worsens)

Descriptively, we show that police unions donate frequently in mayoral elections—especially in mid-sized and large cities. They are more likely to support winning candidates and incumbents, consistent with an “investor” model of political giving. No clear partisan bias in donations.

It took years of data collection to assemble the first large-scale dataset on local campaign finance in U.S. mayoral elections (2,249 elections across 1,039 cities in 43 states). We hope it will facilitate future research on the influence of local interest groups!