The Carnegie Mellon study considers two ways to recoup the funds EV drivers aren’t paying in gas taxes: a usage tax of two cents per mile, and an annual registration fee of 0.6 percent of the car’s MSRP. Neither is likely to happen. The government isencouraging people to buy EVs through a $7,500 federal tax credit. It probably would be loathe to do anything to undermine that campaign. “The goal [of the government] right now is to increase adoption of EVs,” says Professor Inês Azevedo, an associate professor of engineering and public policy at CMU, and an author of the study.