Statistical Analysis Videos

Welcome to our video on police statistical analysis, where we’ll explore how data is used to understand and improve law enforcement practices. We’ll dive into the “problem of the denominator,” a key issue in interpreting crime statistics, and discuss how it can impact our understanding of racial bias in policing. You’ll learn about the role of proxies, using census data, and the importance of choosing the right benchmarks—like the available population or criminal participation rates—to ensure accurate and fair analysis. Join us as we break down these complex concepts and their implications for social justice.

Hit rate analysis in policing measures the effectiveness of certain actions such as traffic stops, searches, or patrols. It is calculated by finding the percentage of these actions that result in finding something of interest, such as contraband or evidence of a crime. For instance, if police officers stop 100 cars and find illegal items in 10 of them, the hit rate would be 10%. This analysis is crucial for police departments to assess the efficiency and fairness of their practices, ensuring that resources are used effectively, and actions are justified.

This video will cover “controlling for a variable,” which is crucial in data analysis. In this video, we will use a public health issue to demonstrate how controlling for certain factors, such as income, can offer a clearer picture of health outcomes. By taking income differences into account, we can avoid drawing misleading conclusions.

You may review these resources for related information:

Goel, S., Rao, J. M., & Shroff, R. (2016). Precinct or prejudice? Understanding racial disparities in New York City’s stop-and-frisk policy. The Annals of Applied Statistics, 10(1), 365–394. https://doi.org/10.1214/15-AOAS897

Recent studies have found racial disparities in stop-and-frisk tactics. Analysis of three million stops in New York City revealed that in over 40% of cases where officers suspected someone of carrying a weapon, the likelihood of finding a weapon was less than 1%. This raised concerns about whether the legal requirement of “reasonable suspicion” was being met. The study also found that blacks and Hispanics were disproportionately stopped in these low-hit-rate contexts. The analysis suggested that a more statistically informed stopping strategy could help recover the majority of weapons while mitigating racial disparities in who is stopped.

Ly, L. (2021). Racial Profiling: Understanding the Practice of Stop-and-Frisk in New York City. Spectra Undergraduate Research Journal, 1(2). https://doi.org/10.9741/2766-7227.1006

Racial profiling in modern policing has led to the unfair scrutiny and harassment of people of color. A study on the New York Police Department’s stop-and-frisk practices found that they were racially profiling black civilians. Recent data from the NYPD suggests that post-Floyd, racial profiling of black civilians still persists and there is a relationship between race and the number of stops, frisks, and arrests. This contributes to the wider consensus that racial profiling and discrimination are present in police practices in the United States.

Statistics. (n.d.). Retrieved September 6, 2022, from https://openresearchlibrary.org/viewer/6d42995c-ebc6-4ba8-b129-ca40983b8896

Introductory Statistics follows the scope and sequence of a one-semester, introduction to statistics course and is geared toward students majoring in fields other than math or engineering. This text assumes students have been exposed to intermediate algebra, and it focuses on the applications of statistical knowledge rather than the theory behind it.

About the video creator: Fritz Umbach is an assistant professor of history at the John Jay College of Criminal Justice at CUNY