QnAs with Jeremy J. Michalek and Corey D. Harper

App-based ride-hailing services, such as Uber and Lyft, have largely replaced traditional taxi services across much of the United States over the past decade.Such services have the potential to address long-standing racial disparities in service quality and accessibility in the taxi industry.In a recent PNAS article ( 1 ), Jeremy J. Michalek and Corey D. Harper, both of Carnegie Mellon University in Pittsburgh, Pennsylva nia, and their colleagues explored disparities in the wait times of Black and White riders using ride-hailing services in Chicago.The authors used publicly available data to simulate millions of trips across the city.Prior research ( 2 ) suggests that Black riders have their ride requests on apps canceled twice as often as White riders.The authors estimated that this disparity could be the result of at least 3% of drivers discriminating by race.Because apps rapidly rematch riders to new drivers, the net effect of driver discrimination was a comparative increase in wait times of only 11 seconds for Black riders, on average.However, the effects of segregated residential patterns resulted in Black riders waiting an average of 50% longer than White riders, even without driver discrimination.PNAS spoke with Michalek and Harper about their research.