Uber has long claimed that its platform prevents drivers from engaging in discriminatory practices, like refusing to pick up people of color, but a new study suggests that Uber and other ride-sharing apps haven't stopped drivers from racially and sexually discriminating against passengers.

According to a study conducted over two years by the National Bureau of Economic Research, black passengers are more likely to wait longer for a ride or have their ride canceled than their white counterparts, while women are likely to be taken on longer rides by drivers who either want to charge them more money or flirt with them (or both).

The study involved nearly 1,500 rides in Seattle and Boston, and the findings are based almost entirely on data from Uber rides, since Lyft displays the rider's name and picture before a driver chooses to accept the ride, making discrimination nearly impossible to quantify.

In Seattle, undergraduate students from the University of Washington were given identical phones with Uber and Lyft pre-downloaded and told to take a few pre-determined routes. They were instructed to note what time they requested the ride, when the ride was accepted by the driver, what time they were picked up, and when they got to their destination. The results showed that wait times for black passengers were up to 35 percent longer than they were for white drivers.

In Boston, researchers set up two different Uber and Lyft accounts for each rider—one with an "African-American-sounding" name and one with a "white-sounding" name—and had passengers order rides from both. ("White" passengers had names like Allison, Brendan, and Brad while "black" passengers had names like Aisha, Hakim, and Darnell).

In Boston, profiles that appeared to belong to black men had a cancellation rate of 11.2 percent, compared to just 4.5 percent for passengers who appeared to be white men. Passengers believed to be black women had a cancellation rate of 8.4 percent, compared to 5.4 percent for white women.

Although neither study was conducted in New York, the data suggests a trend of discrimination that isn't limited to a single city. Most troublingly, the study showed that areas with lower population density—transit deserts especially—riders with "black-sounding" names had their rides canceled at three times the rate white passengers did.

Last year, in the midst of the ride-sharing company's battle with the city, Uber released an ad that suggested the Mayor's proposal to put a temporary cap on Uber rides would disproportionately affect riders in the outer boroughs, especially people of color.

"While taxis often refuse people in minority neighborhoods, Uber's there," the ad said.

Last July, Uber began to encourage drivers to "position" themselves in the "busiest areas of the city" if they wanted to earn a guaranteed $5,000 per month. In New York, these busy areas—Manhattan below 110th Street, and a small chunk of Brooklyn from Greenpoint to Park Slope—happened to avoid the outer boroughs almost entirely.

A report from August 2015 showed that Uber picks up more outer-borough passengers than yellow cabs—but the data also showed that the majority of Uber rides still originated in Manhattan. Either way, the recent NBER study challenges Uber's claims that their platform discourages discrimination.

Uber countered that despite the data, their service is improving transportation for people of color.

"Ride-sharing apps are changing a transportation status quo that has been unequal for generations, making it easier and more affordable for people to get around—no matter who they are or where they live," Rachel Holt, Uber's head of North American operations said in a statement.

"Discrimination has no place in society, and no place on Uber. We believe Uber is helping reduce transportation inequities across the board, but studies like this one are helpful in thinking about how we can do even more," she said.

Lyft, meanwhile, spun the data to suggest that their drivers don't discriminate against passengers of color—even though it's difficult to quantify discrimination on the app, which shows drivers photos of passengers before they approve a ride, meaning a driver can refuse black riders without anyone finding out.

"Because of Lyft, people living in undeserved areas—which taxis have historically neglected—are now able to access convenient, affordable rides. And we provide this service while maintaining an inclusive and welcoming community and do not tolerate any form of discrimination," Lyft spokesperson Adrian Durbin told Gothamist via email.

The authors of the study included a list of suggestions for ride-share providers, including offering fixed fares to avoid extended rides for female passengers; increasing disincentives for driver cancellations; and removing names from passenger identification.

Spokespersons for Uber and Lyft did not immediately respond to whether the companies will take the report’s suggestions into account.