Male drivers at Uber tend to make more money per hour than their female colleagues thanks in part to their lead feet.

That is one of the conclusions of a study released Tuesday into the gender pay gap at the ride-hailing startup that Uber conducted with data scientists at Stanford University and the University of Chicago. The researchers' analysis of more than 1 million drivers at the startup found that male drivers earned 7 percent more than women.

The gender pay gap is one of many diversity issues confronting companies in the tech industry. Silicon Valley has faced tough questions about the treatment of women and minorities, and the industry continues to struggle with recruitment, retention and promotion.

Tech is certainly not the only industry wrestling with pay inequities. Women in North America made 28 percent less than men in 2017, according to a report by the World Economic Forum. That pay gap was larger than the difference in Western Europe (25 percent) but much smaller than the gap in North Africa and the Middle East (slightly less than 40 percent).

The researchers cited men's preference for driving faster than women, as well as working more hours and choosing more lucrative locations to serve.

"Male drivers accumulate more experience than women by driving more each week and being less likely to stop driving with Uber," the study concluded. "Because of these returns to experience and because the typical male Uber driver has more experience than the typical female -- putting them higher on the learning curve -- men earn more money per hour."

Uber declined to comment beyond the report's contents.

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