Aaron Fernandez / BuzzFeed News

On Monday, Uber released a report on driver earnings, conducted by the company's head of economic research Jonathan Hall and Princeton economist Alan Krueger. Hall and Krueger used data from a diverse group of drivers in 20 markets. They found that the majority of Uber drivers drive 15 hours or fewer per week, and that the average Uber driver earns an average wage of $18.75 an hour, before expenses. (Krueger was previously a paid consultant for Uber, but the company says he was not paid for his work on this study.)

Jonathan V. Hall and Alan B. Krueger / National Bureau of Economic Research

Uber released a survey of driver earnings in 2015; this new report is an update of that survey, revised to include estimations of driver expenses — how much drivers spend on gas, car maintenance, insurance, and taxes. It also looks at whether the amount of time drivers spend working per week influences their hourly earnings, and how driver earnings change over time, especially following price cuts. According to the report, which used data from AAA, a full-time Uber driver driving a small sedan would have about $3.76 in expenses per hour, while the same person driving an SUV with four-wheel drive would have expenses of around $5.94 per hour. These conclusions about driver expenses are similar to those made in a June BuzzFeed News investigation, which found that in late 2015 in three cities, working for Uber cost drivers $3.50 to $5 an hour, and which didn't take car size or full-time versus part-time into account. However, this report doesn't take geographical location into account, which is important because the amount of rain or snow a vehicle experiences can impact the cost of maintaining it.

Jonathan V. Hall and Alan B. Krueger / National Bureau of Economic Research