Statistical Issues in Analyzing Misconduct in Policing

Oregon Convention Center 

Data collection on police-civilian encounters is generally designed for law enforcement purposes, rather than statistical analysis of police misconduct. This gap poses challenges for policymakers and applied researchers seeking to draw reliable inferences from this data. A recent National Institute of Statistical Science forum brought together statisticians and researchers to discuss the state of the field and next steps. We first review key data limitations such as selection and mismeasurement—i.e. omission of encounters where officers choose not to detain civilians and inaccuracies in officer accounts of civilian attributes/behavior. We then formally define estimands that quantify the amount of police force that is (1) discriminatory, (2) unjustified under department policy, or (3) outlying compared to the levels typically used by other officers. We review how common practices in applied research lead to statistical bias in estimation of these quantities. Finally, we discuss how recently proposed estimators and partial identification procedures address some of these concerns, and we highlight a number of open questions and important directions where statisticians can contribute.