We report the first empirical estimate of the race-specific effects of larger police forces in the United States. Each additional police officer abates approximately 0.1 homicides. In per capita terms, effects are twice as large for Black versus white victims. At the same time, larger police...

How do political leaders affect constituents' beliefs? Is it rhetoric, leader identity, or the interaction of the two that matters? Using a large-scale experiment we decompose the relative importance of partisan messages vs leader sources, in the context of beliefs about immigration....

We examine how changes in the salience of workplace risk affect police behavior and public safety. Specifically, we investigate cases of police officer deaths while on duty. Officers respond to a peer death by decreasing arrest activity for one to two months, consistent with heightened fear....

How does immigration enforcement affect public safety? Heightened enforcement could reduce crime by deterring and incapacitating immigrant offenders or, alternatively, increase crime by discouraging victims from reporting offenses. We study the U.S. Secure Communities program, which expanded...