This paper evaluates the effect on crime of creating a fundamental modern-day institution: centralized professional … police forces tasked with preventing crime. We study the 1829 formation of the London Metropolitan Police - the first … professional force worldwide. Using newly digitized and geocoded crime and police data together with difference-indifferences and …

between the racial composition of a city's police force and the racial patterns of arrests and crime. Increases in the number … police officers has a less clear-cut impact on crime rates. It appears that own-race policing may be more effective in … reducing property crime, but no systematic differences are observed for violent crime. These results are consistent either with …