CHICAGO, Feb. 8 (Xinhua) -- Male Uber drivers in the U.S. earn 7 percent more per hour than their female counterparts mostly because they drive faster, a new study says.

The report was released Wednesday after economists from the University of Chicago and Stanford University and Uber examined the data of over 1.8 million Uber drivers in the United States. About 27 percent of them were women.

"Surprisingly, we find that there is a roughly 7% gender earnings gap amongst drivers," the report said.

It said that though the algorithms for Uber's car-hailing system were "blind" to race, gender and sexuality, they did not take into account differences in driver behavior, which can vary between men and women.

One of the reasons for the earning gap, the report said, is that men drive about 2 percent faster than women, which allows them to make more trips. Moreover, men are also likelier to drive in more lucrative areas than women. For example, they complete more trips to and from airports than women do.

The paper appeared as Uber tries to redeem its reputation after a series of scandals.

"Overall, our results suggest that even in the gender-blind, transactional, flexible environment of the gig economy, gender-based preferences can open gender earnings gaps," the study concludes.

In a blog post, Uber said the study "produced no evidence that outright discrimination, either by the app or by riders, is driving the gender earning gap."

According to data from the U.S. Census Bureau, women earned just 82 percent of what men earned in 2016.