Female Uber drivers make less than their male counterparts, but it's not what you think

Even driving Uber while female comes with a pay gap -- but it's different from the systemic problem of lower pay seen in other industries.

Stanford, University of Chicago, and Uber economists looked at more than a million Uber rides in the U.S. from January 2015 through March 2017 and found a roughly 7 percent gap. This lower hourly pay rate is due to several factors including driving speed and experience gaming the app.

Drivers are paid based on a formula that doesn't include gender -- just miles, time on the road, a surge multiplier, and some other ride-based incentives -- so gender shouldn't impact pay. But the gap exists anyhow. Women on average earn $20.04 an hour, while men bring in $21.28.

Before we get into the details, let's remember that the causes for Uber's pay gap, which can largely be based on driver choices, shouldn't undermine very real systemic issues in other industries. Women working full-time in the U.S. on average earn only 88 cents to every dollar a man earns, and that's not just because of choices they make concerning careers and family life. Unconscious bias, sexism, stereotypes, and other factors play a role, too.

In the case for Uber drivers, the economists found in a new working paper the lower pay could be because of three factors: experience using the Uber platform, drivers' time and location preferences, and driving speed.

Women are more likely to work on Sunday afternoons, for instance. Also men are more likely to stay an Uber driver for longer -- the attrition rate for women sticking with driving after six months is higher: 76 percent compared to 63 percent for men. So men become more experienced at milking the most out of the app because they stick with it longer; they learn the best places and times to pick up riders and other tricks.

In an Uber blog post about the study, the company said, "It is a complex issue with no quick fixes." But one idea suggested to help women catch up to men's earnings was to share the tricks and other ride-sharing knowledge as well as make it easier to learn the app. Basically, the idea is to get rid of the "more experience" advantage that tends to give male drivers a boost.

While the pay gap is partly because of experience, time spent, and location preferences, these differences only account for about 50 percent of the gap, the researchers found.

As far as discrimination leading to the gender pay gap, the researchers couldn't find evidence of that in play. It didn't look like customers prefer a male or female driver -- it's not like any time a woman driver is matched customers reject them. In an Uber blog post about the pay gap, the company reiterated the findings that "no evidence that outright discrimination, either by the app or by riders, is driving the gender earnings gap."

So something else is mostly leading to the pay loss: driving speed.

A few of the economists spoke to the Freakonomics Radio podcast this week about the study that looked at 1,877,252 drivers. Of those 1.8 million drivers, only 27 percent were female (that's 513,417 women drivers). The study's authors determined half of the reason for the 7 percent difference in pay was because of how fast drivers are driving.

Men in general usually drive faster than women, and that becomes a big factor when driving for Uber.

Stanford professor Rebecca Diamond said during the podcast, "Men happen to just drive a little bit faster, and because driving a little bit faster gets you to finish your trips that much quicker, and get on to the next trip, you can fit more trips in an hour, and you end up with a higher amount of pay."

John List, University of Chicago economics professor and Uber economist, knows that the data points to driving speed mainly factor into the pay difference. But he thinks social constraints could also affect female driver's opportunities to make more trips and stay a driver longer. With women more likely to be the family caretaker, with duties like taking the kids to school or soccer practice, they miss out on money-making driving time and experience.

"As policy makers, what we want to do is make sure that we can alleviate those constraints as much as possible," List said on the podcast.

The study looked at Uber data before tipping was offered in the app. The researchers say it already looks promising that women are receiving higher tips than men -- somewhere between 10 to 20 percent more.