This study takes a detailed look at this issue in urban America, examining how the fraction of homicides for which an arrest is made (the homicide clearance rate) not only varies by the characteristics of the victim but also across cities, even when the characteristics of the victim are the same. Specifically, I studied the extent to which city police budgets impact homicide clearance rates. This issue is particularly important given that one of the most visible calls for action coming from protests in the summer of 2020 was to “defund the police.” While “defunding the police” was not always well-specified, many city leaders responded to these calls by saying they would cut their police budgets. Over the course of 2020, numerous prominent cities, including Austin, New York City, San Francisco, Portland, Philadelphia, Baltimore, and Washington, DC, all suggested they would make significant cuts to their police budgets. This study sheds light on the potential consequences of such budget moves in solving homicides.
I used a data set collected by the Washington Post that contains information regarding all homicides that took place in 50 of the largest American cities between 2007 and 2017. These data generally include age, race, and sex of the victim, along with the city and the place the victim was found in the city. I supplemented the Washington Post homicide data with city and neighborhood economic and demographic data from the American Community Survey to further assess how homicide clearance rates varied by city and neighborhood characteristics. I then used city budget data to assess the impact of police budgets on homicide clearance rates.
Consistent with previous studies, the data I used reveal that the average homicide clearance rate across large American cities during this period was about 60 percent. Well over half of homicides in these large cities over this period comprised adult minority males murdered in a heavily minority neighborhood. Moreover, the clearance rate for such homicides is generally 15–30 percentage points lower than it is for adult white male victims, adult female victims of all races, and child and elderly victims of all races and genders. There is also substantial variation in homicide clearance rates across cities, with the top five cities clearing over 75 percent of homicides over this period and the bottom five cities clearing less than 45 percent. I found that while per capita police budgets also vary quite widely across cities, and across years within cities, there is no evidence that such variation has any significant relationship with homicide clearance rates. This result is quite precisely estimated and remains after accounting for city, neighborhood, and victim characteristics, including recent homicide and unemployment rates. It is possible that current and expected future crime conditions influence police budgets (rather than police budgets influencing crime conditions), which could produce an inaccurate estimate of the effect of police budgets on clearance rates. However, I accounted for this and continued to find no evidence that greater police budgets increase homicide clearance rates.
Overall, this study is not able to directly determine what would happen to homicide clearance rates if large U.S. cities were to dramatically cut or increase their police budgets. However, the results reveal that over the last decade, variation in police budgets across and within large American cities has had no discernable impact on catching more murderers.
NOTE
This research brief is based on David Bjerk, “Does Greater Police Funding Help Catch More Murderers?,” Journal of Empirical Legal Studies, July 20, 2022.