Thursday, September 25, 2008

Do Cops Reduce Crime? Sociologists vs. Economists

Each day UCLA emails me a news blast highlighting important new work by UCLA faculty. Below I report one that examines whether a Los Angeles police effort has reduced crime.

The full report is available here:

If you are an intellectual who likes to read and think, please contrast that paper
with this paper:

In "Causality studies", the usual issue is imputing the counter-factual; what would have happened in the absence of the treatment. You must decide which paper has the more convincing empirical design.

Study finds police crackdown in skid row did not reduce serious, violent crime

Lauri Gavel,


Sara Wolosky,


Two years after the city of Los Angeles launched the Safer Cities Initiative (SCI), representing one of the most targeted concentrations of police resources in the world outside of Baghdad, a UCLA School of Law study has found that the effort has failed to reduce serious or violent crime in the city's skid row area.

"While there was a reduction in overall crime in skid row, it was strikingly similar to the reduction seen in areas outside the initiative's focus," said UCLA law professor Gary Blasi, who conducted the study. "Importantly, our study shows there was no statistically significant effect on serious, violent crime in Skid Row, with the exception of a very small effect as to the crime of robbery."

Serious, violent crimes are defined by law-enforcement officials as homicide, rape, robbery and aggravated assault. A UCLA School of Law report released last year — "Policing Our Way out of Homelessness?" — noted that during the first seven months of the initiative, just 0.7 percent of the arrests by the 50 officers assigned to the Safer Cities Task Force were for serious, violent crimes.

"Our study shows that the Safer Cities Initiative did not cause the overall decline in skid row crime," Blasi said. "Even if we attribute the decline in skid row robberies to the SCI, each additional officer was responsible for a reduction of just under one robbery per year. One can argue that the same 50 officers might have had much more impact on serious or violent crimes in other parts of Los Angeles with higher rates of such crimes."

According to Blasi, the additional police officers assigned to the 50 square blocks of skid row cost the city general fund about $6 million, more than was spent on shelter for the homeless across the entire city. When the Safer Cities Initiative was announced in 2006, it was supposed to include two components: increased enforcement and increased services.

"The enforcement component was delivered swiftly, with 50 additional patrol officers and 25 to 30 additional narcotics officers and mounted police assigned to the 50 blocks of skid row," Blasi said. "However, the enhancement part of the equation — more shelter, drug treatment and services for homeless people with mental disabilities — never materialized, and we are all worse off as a result."

The new study — "Has the Safer Cities Initiative in Skid Row Reduced Serious Crime?" — is available at

"Policing Our Way out of Homelessness" (2007) can be found at

The UCLA School of Law, founded in 1949, is the youngest major law school in the nation and has established a tradition of innovation in its approach to teaching, research and scholarship. With approximately 100 faculty and 970 students, the school pioneered clinical teaching, is a leader in interdisciplinary research and training, and is at the forefront of efforts to link research to its effects on society and the legal profession.