After more than two weeks of unusual killings and robberies in Washington DC, Police Chief Charles H. Ramsey has called a crime emergency. During a crime emergency the Chief can increase shifts and get more police on the street. This is exactly the right thing to do. My research with Jon Klick shows that crime in Washington DC falls significantly during high terror-alert periods when the police double up on shifts much as they do during a crime emergency.
More generally, when one combines estimates of police effectiveness that come from myself and Klick, Steve Levitt, Bill Evans and Emily Owens and others with data on the costs of hiring police, it’s clear that police are a bargain. We could double the number of police in the United States and the costs of crime would fall by substantially more than the cost of police. (Reallocating police and prison space from drug users to violent criminals would also help.)