City Hires Independent Firm, Led by Nationally-Renowned Harvard Economist, Who Finds No Evidence of Systemic Racial Bias in Police Searches

Results Are Based on Numerous Statistical Tests That Used 2024 Stop and Search Data

Thursday, October 23, 2025 - Cleveland - The City of Cleveland announced a new partnership with Sigma Squared, a data analytics company, to evaluate datasets aimed at uncovering whether racial disparities exist within the Cleveland Division of Police (CDP). This partnership fulfills a prior pledge made by the Bibb Administration to hire an independent organization to conduct a comprehensive analysis of CDP's stop and search data. The City asked Sigma Squared to specifically examine investigatory and traffic stops and searches from 2024, given that it's the most recent full-year of data available. When controlling for other contextual data points - including interaction circumstances, location, and stop reason - the firm found no statistically significant racial disparities in the rates at which searches were conducted by CDP officers.

"The raw data we announced to the community last year was just that - a preliminary baseline that lacked the critical context to draw any sort of definitive conclusions, which is why I urged caution in rushing to judgment and committed to having outside experts look further into the data. This new partnership with Sigma Squared fulfills that promise and their analysis provides us with the needed context that ultimately revealed no evidence of systemic racial bias," said Mayor Justin Bibb. "This level of objectivity, by opening up our books to be rigorously reviewed by an outside firm, is the key to improving transparency and building trust with the community. If future analyses indicate we need to make changes - whether that's just one neighborhood or district, or across the entire Division - the community can rest assured that we will take corrective action to address those issues head-on."

"This certainly isn't a mission accomplished moment, but these initial results are a great step in the right direction," added Mayor Bibb.

Sigma Squared's team is led by Dr. Roland Fryer, a Professor of Economics at Harvard University who was awarded a MacArthur "Genius" Fellowship and the John Bates Clark Medal -- given by the American Economic Association to the best American Economist under age 40. At age 30, Dr. Fryer became the youngest African-American to receive tenure at Harvard. He has was also recognized by The Economist in 2008 as one of the top eight young economists in the world.

Sigma Squared uses the only evidence-based policing platform, utilizing peer-reviewed algorithms, to help law enforcement leaders better understand, measure, and optimize agency impacts. Their approach is rooted in empirical research and is the gold standard for determining whether racial disparities exist. Their analysis goes beyond just comparing baseline data of which individuals were being stopped and searched - they take it a step further to account for how, where, when, and why those stops and searches were happening. Their methodology doesn't just look at race, it considers a host of variables - including gender, age, police precinct, reason for stop/crime type, time of day, neighborhood, type of ID provided, contraband, and several others. This holistic approach allows them to create control groups for various factors - so they can definitively conclude whether individual variables (like race) do in fact influence outcomes (thus suggesting bias) or can be ruled out as non-determinative.

"The relationship between law enforcement and the communities they serve is extraordinarily important," said Dr. Roland Fryer, Professor of Economics at Harvard University, and CEO & Co-Founder of Sigma Squared. "If we rely solely on population percentages to judge police activity - assuming that a group's share of stops must equal its share of the population - we risk eroding trust and overlooking the real drivers of public safety. Through this partnership, Cleveland is using rigorous, near real-time data to distinguish between disparities and actual bias. Looking at all the data from 2024, we find no evidence of bias."

"The true power of this approach is ongoing: by examining the data every few weeks, Cleveland can detect small concerns early and address them before they grow," added Dr. Fryer. "And throughout this process, we will continue listening to community voices. Data doesn't replace dialogue - it enhances it."

Sigma Squared utilizes a contraband hit-rate test and threshold test - both industry standards that look at the effectiveness of stops among other things - to determine whether there is evidence of bias during stops and searches. If, after adding controls to account for important context, the hit rates of two different demographics are not similar - that would indicate bias (e.g. African-Americans being stopped at higher rates but had lower amounts of contraband). Sigma Squared analyzed CDP stops and searches across 2024 and found no evidence of racial or gender bias.

"Sigma Squared's independent assessment is welcoming news, but it's not a victory lap for us. Our oversight efforts will continue here at the local-level," said Dr. Leigh Anderson, Executive Director of the Police Accountability Team. "We hope this will facilitate meaningful community conversations and encourage residents to share their thoughts, as they are the ones that will continue to guide this important work."

The City's partnership with Sigma Squared will continue beyond this analysis. The City, through Sigma Squared's technology, will have access to their dashboard and be able to receive analyses as-needed. This is a significant upgrade from how the City currently operates by compiling spreadsheets from systems, manually reviewing the trends, and reporting out findings on an annual cadence - an outdated and often tedious process.

"We are excited about this new partnership with Sigma Squared, which will allow us to receive data-driven analytics much more quickly. This will help improve our procedures, streamline our processes, and operate more efficiently - as we'll now have the ability to adjust based on real-time insights rather than looking back on old data," said Dorothy Todd, Chief of the Cleveland Division of Police. "I'm also pleased to hear the results of Sigma Squared's stop and search analysis, and I hope it's something that both residents and officers can find comfort in as we continue working to improve public safety and trust within our community."

As always, anyone who is interested in joining the Cleveland Division of Police should contact the Recruitment Unit at (216)-623-5233.