https://jalopnik.com/ev-credits-mostly-go-towards-rich-people-who-would-buy-1835233701
From the study:
Our results suggest that vehicles that EVs replace are relatively fuel-efficient: EVs replace gasoline vehicles with an average fuel economy of 4.2 mpg above the fleet-wide average and 12 percent of them replace hybrid vehicles. Federal income tax credits resulted in a 29 percent increase in EV sales, but 70 percent of the credits were obtained by households that would have bought an EV without the credits.
And, for the 109,449 EVs purchased in 2014:
Among gasoline vehicles replaced by EVs, 74 percent of them have fuel economy above 25 mpg. The vehicle models that were replaced by EVs most are: Honda Accord, Toyota Prius, Toyota Camry, Honda Civic, Toyota Corolla, Nissan Altima, and Chevrolet Cruze. This substitution pattern suggests that EVs mainly attracted consumers who were originally choosing mid-size and fuel-efficient gasoline or hybrid vehicles, rather than gas-guzzlers such as large SUVs or trucks.