Tagged: police

Police Stops and Naïve Denominators

by · Aug 11, 2025 12:19 pm

In their 2025 article published in Crime Science, Jerry Ratcliffe and Shelley Hyland critically examine how reported racial disparities in police stop data can be misleading. They argue that much of the misrepresentation stems from the widespread use of an inappropriate baseline, or “denominator,” when calculating stop rates.

Typically, analysts compare the distribution of police stops across different racial groups to the distribution in the total city population. Unfortunately, this method does not account for differences regarding who is actually more or less likely to encounter police stops. In doing so, this approach ignores important factors such as the uneven geographic distribution of crime and variations in police deployment. According to the authors, by relying on this “naïve denominator,” studies risk overstating racial disparities. Ratcliffe and Hyland’s work challenges researchers, policymakers, and the public to reconsider how police stop data should be interpreted to paint a more accurate and nuanced picture of racial bias in law enforcement.

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Understanding the 2020–2021 homicide spike in the U.S.: Causes, variations, and recovery patterns

by · Jun 2, 2025 10:34 am

The United States experienced a sharp rise in homicide rates during 2020–2021, prompting widespread research into one of the most significant crime surges on record. A recently published study by the Manhattan Institute analyzed homicide patterns in 78 large cities, identifying shifts in city-level trends and exploring links to policing disruptions, social unrest, and pandemic-related economic changes. While the study was not designed to evaluate criminal justice reform initiatives, its findings have implications for understanding the social context in which many of these programs were implemented.

Researchers found that the spike in homicides was tended to be more severe in cities and communities already struggling with high baseline violence, with contributing factors including reduced police staffing, disrupted public services, and concentrated group-related gun violence. Surprisingly, unemployment shifts during the pandemic were not consistent predictors of rising homicides, challenging common assumptions.

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The power of communities in crime prevention: Insights from Baltimore

by · Apr 12, 2024 11:08 am

Crime tends to be concentrated in specific areas within cities, with about 50% of crime occurring on just 5% of streets. One police strategy that can help combat this is known as “hot-spot policing,” which has been shown to reduce violent crime in multiple studies.  Another factor that can help reduce crime in an area is when citizens exercise “informal social control.” Informal social control refers to the ability of community members to regulate behavior and maintain order through cohesive relationships, mutual trust, and willingness to intervene.  It involves residents taking actions to prevent and address crime and disorder in their neighborhoods.

One common assumption is that the chatoic and disordered nature of high-crime hot spots renders residents incapable of playing a significant role in crime prevention. However, a new study conducted in Baltimore seems to reveal otherwise.

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Vallejo, CA officially declares state of emergency over police shortage

by · Aug 1, 2023 12:10 pm

Last week, the city of Vallejo, California officially declared a state of emergency due to its lack of police officers, Daniel Egitto of the Vallejo Times-Herald reports. Over the last several months, the Vallejo Police Department (VPD)’s officer shortage has been worsening, with five officers leaving since March, and another three scheduled to leave within the next month.

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PA state police data shows no racial profiling in traffic stops: Study

by · May 25, 2023 12:35 pm

The question of racial bias in police traffic stops is a highly debated issue. Some analyses have shown that certain racial or ethnic groups are disproportionately represented in traffic stops, leading many people to allege racial profiling and discrimination. However, it is not accurate or fair to claim that all police traffic stops are inherently racist. Other factors can contribute to racial disparities in police stops, including differences in driving behavior, geographic location, and crime rates in specific areas. As more research is conducted on this topic, it becomes more apparent how much context and other factors can play a role in traffic stop decisions. For example,  research that adequately accounts for the impact of contextual and situational factors has found that racial disparities may not be as pronounced as previously thought, and that they are often explained by other factors unrelated to race.

This was the case in a recent study examining traffic stops in Pennsylvania, which found no evidence of racial profiling. According to the full-length report, the Pennsylvania State Police (PSP) stopped more than 440,000 drivers in 2022, 78.5% of whom white. In comparison, 14.4% were Black, and 8.2% were Hispanic. To conduct the study, the PSP partnered with Dr. Robin Engel and the National Police Foundation to ensure that the evaluation was independent and external to the department. Overall, these data should inspire public confidence in the police. It also suggests that PSP’s approach could serve as a promising model for other agencies.

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Unsound statistical analysis misrepresents racial profiling in California police stop data

by · Jan 30, 2023 1:53 pm

Findings from the California’s Racial & Identity Profiling Advisory (RIPA) Board’s Annual Report released earlier this month have sparked controversy after the results revealed that nonwhites are dispropotionately represented in police stops. The report also claimed that, of those stopped, nonwhites were searched more frequently, arrested more frequently, and more frequently engaged in physical confrontations with police officers. This led many people to conclude that the police are in fact, racist. However, it’s important to note that the practice of policing is far more complicated than what can be captured in datasets. While these data appear straightforward, studying racial bias is complicated.

There are myriad contextual factors at play that affect officer decisionmaking and police-citizen interactions, such that it is nearly impossible to attribute racial disparities solely to any one cause. Unfortunately, contextual factors are often not easily measured, or they might be ignored on the basis that these details are “less important.” But ignoring these key details leaves us with an incomplete understanding of the dynamics influencing these police encounters. So when it comes to the RIPA Board’s report, the findings seem straightforward, but a closer look shows some holes in the methodology that likely undermine the validity of the findings. To this end, the Peace Officers Research Association of California (PORAC) conducted a critical analysis of the report that highlighted numerous problems with the RIPA data and the methodology used in the report. In this post, I will summarize the key issues raised by the PORAC.

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Misconceptions about racial disparities in police investigations: Results from Tucson

by · Nov 4, 2022 11:13 am

Debates about racial inequalities in the criminal justice system have ramped up in the last several years. This has been largely driven by discussions about racially-biased police violence, but many also speculate about disparities in how the police treat crime victims. For example, one common belief is that the thoroughness of police investigations varies based on victim and officer race. But a recent study published in The Journal of Law and Economics (subscription required for access) suggests otherwise, at least in the context of residential burglary.

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FBI releases first quarter of crime data for 2022

by · Jun 9, 2022 2:20 pm

Earlier this week, the FBI released the first quarter of crime data for 2022. There has been no official government report published at this time, though I examined the data to get an idea of whether crime increased or decreased relative to the first quarter of 2021. Unfortunately, I was unable to compare the data to quarter one of 2019 and 2020 as those data are not currently available by quarter.

Rates for all types of crime remained relatively stable, though this may change as we head into the summer. Larceny offenses saw the largest increase, which was only a mere 0.08%, and overall property crime increased 0.05%. The largest decrease was for arson, which decreased by about 0.2%. Rates for murder decreased by .08% (see more details in the table below).

FBI finally releases data from the National Use-of-Force Data Collection

by · Jun 9, 2022 10:04 am

On May 31, 2022, the FBI released national-level statistics on police use of force for the first time ever. These data were derived from the National Use-of-Force Data Collection, which is the first national-level dataset to collect data on police use of force. Law enforcement agencies are not required to submit their data though, so participation rates have been a consistent issue that has prevented the release of information up until this point. The FBI has been reporting on participation rates, but because participation rates have been below the required 60% threshold (up until now), it was unclear whether details on actual use-of-force data would ever be released. Relatedly, there was speculation that lack of participation might even cause the database to shut down.

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