A recent study published in the Journal of Urban Economics examines the impact of Black Lives Matter (BLM) protests on police behavior in the United States. The study compares changes in police conduct between cities that experienced protests during the early Mike Brown era and cities that witnessed protests only during the later George Floyd era. The findings suggest that BLM protests prompted police departments to reduce their interactions with the public and adopt body cameras, resulting in a decrease in police killings but an increase in crime.
Over the five years following local BLM protests, property crime arrests dropped by approximately 12 percent, while reported murders surged by roughly 11.5 percent, leading to over 3,000 additional homicides nationwide. The property-crime clearance rate also experienced an 8 percent decline, indicating a significant decrease in police activity. However, the combined effect of police pullback and the widespread adoption of body cameras led to a remarkable 10 to 15 percent reduction in police killings, equating to approximately 200 fewer deaths across the country.
These findings align with the “Ferguson effect,” a phenomenon where protests drawing attention to officer-involved killings result in less proactive policing. The fear of criticism, lawsuits, or low morale leads to a decrease in law enforcement engagement and a potential increase in violence as some citizens resort to resolving conflicts through violence.
The increase in murders following certain protests has profound implications for social welfare, as violence negatively impacts mental health, sleep patterns, academic performance, and cognitive abilities. The reduction in police killings, on the other hand, is a gain for societal well-being, as police violence has far-reaching consequences, including eroding trust within communities and exacerbating existing problems.