Female Uber drivers in the US earn less than their male counterparts because they drive more slowly and in less lucrative patches, a study found.
The ride-hailing app's algorithm for pay is gender-blind, with each trip - by male or female driver - paid according to a formula based on distance, time taken, and surge pricing.
Economists from Uber Technologies, Stanford and the University of Chicago put the seven per cent gap in drivers' earnings down to women's personal preferences when driving, and not any gender discrimination.
Nearly half of the gap in earnings was said to be because men prefer to drive faster, according to The Gender Earnings Gap in the Gig Economy: Evidence from More Than a Million Rideshare Drivers which studied data from nearly two million drivers based in the US.
Men also tended to drive in more lucrative spots, a factor that accounted for about 20 per cent of the difference in earnings.
Another factor was work experience, since a driver with 2,500 trips under their belt earns 14 per cent more than a driver who has made less than 100.
Male drivers made more trips, accumulating experience that taught them when and where to drive to maximise earnings as well as how to strategically cancel and accept trips.
"Male drivers accumulate more experience than women by driving more each week and being less likely to stop driving with Uber," the study said.
Amid increased public debate about the gender pay gap, the researchers believe the study demonstrates that in some parts of the labour market - particularly in the gig economy where higher flexibility allows for more personal choices - it may not be down to simple discrimination.
Asked why women Uber drivers in the US earn less for doing the same work, Stanford graduate business professor Rebecca Diamond told the Freakonomics podcast: "I think they’re not doing the same. That’s what we’re showing, they’re doing different — they’re making different choices in the labour market."
John List, chairman of the University of Chicago economics department, added: "What’s interesting and intriguing is that after you unpack those differences, what you find is that there are perfectly reasonable explanations for what’s happening on the Uber platform."
Asked for further comment Uber pointed the Standard to a blog by Dr Diamond and fellow researchers Jonathan Hall and Cody Cook of Uber.
In it they say: "Understanding the causes of the gender earnings gap is only a first, albeit important, step. It is a complex issue with no quick fixes."
They added that Uber may in future seek to address the earnings difference by offering drivers help to learn the ways to earn more without putting in more hours.
"In the immediate term, one area for further exploration — in the context of ridesharing — may include product improvements that provide drivers with more contextual information to help them move up the learning curve more quickly, regardless of how much or how long they drive," they wrote.