Under the programme, nearly 700,000 “clunkers" were taken off the roads and replaced by more fuel-efficient vehicles. Cars purchased under the programme are, on average, 19 per cent above the average fuel economy of all new cars currently available, and 58 per cent above the average fuel economy of cars that were traded in (United States Department of Transportation, 2009). The database provides a comprehensive annual update of the policy-making process in place since 2000 (www.