This paper assesses the impact of Black Lives Matter Protests in the United States on police traffic stops of civilians. Exploiting variation in protest location across 16 states and protest timing from 2014 to 2018, I use a stacked difference-in-differences methodology to find that the protests led to an 12% reduction in stops and 8% reduction in stops per capita. This was driven by decreases in counties whose inhabitants vote Democrat. Meanwhile, the protests had no effect on the percentage of stopped drivers who are black, tentatively suggesting no change in police racial discrimination. Comparisons of stops in Texas at day and night support the idea that the decrease in stops was driven by increases in police officer caution of public surveillance and scrutiny. Further focus on Texas suggests, however, that this decrease in stops did not come at the cost of police efficiency: there was a 10% increase in the probability a searched car carried contraband, indicative of the protests leading to fewer stops of marginal drivers.
