Oops...

Still, not the most lucrative line of work once you count the costs (source).

A researcher at the Massachusetts Institute of Technology says he's revising a study he co-authored after admitting that "criticism is valid" of initial findings that Uber and Lyft drivers are making a median pretax profit of $3.37 an hour and a vast majority are making less than minimum wage.

Uber said the working paper had "a major error in the authors' methodology."

Using one new method of calculating the median profit that incorporates Uber's criticism, the figure "rises to $8.55 / hour from the $3.37 initially reported," the lead author Stephen Zoepf wrote in a statement posted to Twitter on Monday. And using another alternate method, the median profit goes up to $10 an hour.