CAFE: not so great?

We talked about how improving vehicle gas mileage can cause problems, including the "rebound effect" by which people will drive more when driving is cheaper. Another issue has been uncovered by researchers Mark Jacobsen and Arthur van Benthem: they find that people keep their used cars longer and drive them more when newer cars become more expensive. They conclude that 12-17% of the expected savings from CAFE standards may disappear via this means.