Uber's fought hard against a gender pay gap: Here's why it still exists.

Despite several initiatives meant to curtail pay differences between genders, the recently-embattled Uber continues to see a gender earnings gap exist between men and women. The main reason? Experience.

According to a study published in January by two Uber employees, two Stanford University professors and the chairman of the University of Chicago economics department (who’s also employed at Uber), there’s a roughly 7% gender earnings gap among Uber’s drivers, in spite of efforts by the ridesharing company to prevent that. Those efforts include implementing a gender-blind algorithm, non-negotiable pay and flexible work hours.

But differences between the sexes continues to persist for the company largely because of differences in how, and where, men and women drive. Men not only tend to drive in more lucrative locations, but they also typically drive faster: The authors of the study found that a person who drives faster, regardless of sex, will likely earn more.

Perhaps most importantly, though, is how experience factors into employees’ pay. A driver who’s racked up more than 2,500 trips earns 14% more per hour than the driver who’s completed less than 100, according to the study.

“The fact that we find this dramatic return to experience, where drivers that have had more rides completed in the past makes them more knowledgeable about how to be an Uber driver, is a pretty interesting finding,” said Rebecca Diamond, an assistant economics professor at Stanford University and one of the authors of the study. “You might have thought that it’s a relatively simple, transparent job, but even in that simple job, there’s a steep learning curve.”

It’s also one of the most transferable facts from the study, she said. More experience typically demands higher pay, no matter the job. In almost all jobs, across the field, women worked fewer hours than men and were more likely to take breaks in their career.

In 2017, women who worked full-time on average earned median weekly earnings that were 82% of their male counterparts, according to the U.S. Department of Labor.

Some have expressed hope that as the labor market becomes more flexible -- thanks in particular to jobs like Uber and other contractual work that allow workers to choose their own schedules -- the gender gap could potentially shrink, or close fully. But, Diamond said, that’s unlikely to happen until aspects of society change.

“It’s this return to experience that isn’t really going to go away,” she said. “Unless we have broader changes to social norms.”