When MIT researchers said last week that the median pre-tax hourly income for Uber and Lyft drivers was a mere $3.37, and that 30% of the drivers were losing money rather than making it, Uber was less than pleased. CEO Dara Khosrowshahi quickly hit back, suggesting that MIT stood for “Mathematically Incompetent Theories,” and the company’s chief economist, Jonathan Hall, used a blog post to highlight problems with the researchers’ methodology. Now the lead researcher behind the draft paper has admitted that Uber’s criticism was actually pretty valid—while also asking Uber and Lyft to make more data available, in order to improve his analysis.