CBO Releases a Study on the Effects of Federal Tax Credits for the Purchase of Electric Vehicles
from CBO Recent CBO Publications
CBO estimates that federal policies to promote the manufacture and purchase of electric vehicles (including some policies that support other types of fuel-efficient vehicles) will have a total budgetary cost of about $7.5 billion through 2019. Tax credits for buying electric vehicles—which account for about one-fourth of that budgetary cost—are likely to have the greatest impact on vehicle sales.
http://www.cbo.gov/publication/43633