A study released this summer by CMU’s Heinz College of Information Systems and Public Policy helps fill the gaps. It analyzed the economic opportunity of so-called “non-employer establishments” in the transportation occupations — put another way, self-employed people picking up riders in need of a lift.

The results were clear: The number of self-employed drivers in Allegheny County rose faster than any other county in the state after Uber and Lyft launched here in early 2014.

Yet annual income for each self-employed driver remained low. In 2015, as the number of drivers here more than doubled to nearly 2,500 people, and average income for each fell by $8,000 from $20,000 in 2014.