Specifically, the study stated, drivers who make runs for Uber more frequently are more likely to know where and when to operate in order to get the highest-paying fares.

Thus, because women, on average, spend less time driving for Uber than their male counterparts, they are less likely to be around to grab the highest-paying fares.

“Men’s willingness to supply more hours per week (enabling them to earn more) and to target the most profitable locations shows that women continue to pay a cost for working reduced hours each week, even with no convexity in the hours-earning schedule,” the research team stated.

The study, which was based on data collected from 1,877,252 drivers operating in America from January 2015 to March 2017, examined factors including average hours worked per week, money earned over the whole week, and money earned per hour.
[…]
Overall, the gang concluded that those who drove an Uber car more often were able to make more per trip, and because on average the men surveyed drove 50 per cent more often, they were able to get on average $21.28 (£15.23) per hour compared to $20.04 (£14.35) logged by their female counterparts.

With more time driving, we’re told, comes a better idea of when and where the best fares are to be expected.
[…]
“A driver with more than 2,500 lifetime trips completed earns 14 per cent more per hour than a driver who has completed fewer than 100 trips in her time on the platform, in part because she learns where to drive, when to drive, and how to strategically cancel and accept trips.”

At least one other factor was cited in the gap: speed.

The study found that while driving for Uber, men tended to drive around 2.2 per cent faster than women. This meant that, over the long haul, they were able to rack up a few extra trips and make a bit more money.

“Increasing speed increases expected driver earnings in almost all Uber settings,” the research team concluded.

Source: Uber: Ah yeah, we pay women drivers less than men. We can explain!