Driving around in an SUV may make you feel safer, but it is more dangerous to those around you, especially if non-SUV drivers are involved in an accident with an SUV. Michelle White, an economist at the University of California at San Diego, estimated that for each fatality that SUV drivers avoid for themselves, they cause four fatalities involving car occupants. Why?

Larger autos are supposed to be safer for occupants, but their designs make them more dangerous for others. Stiff panels on the SUV transfer more force to other vehicles, SUV bumpers don't align well with car bumpers, and the fact that they are larger causes more damage to car occupants' upper bodies and heads in collisions. The significant savings in safety for the driver of an SUV translates to significant costs for others.

Consider the following: If everyone in town drives a car, then a person is best off buying an SUV because of the safety factor. But this is harmful to society as a whole because of the safety costs imposed on others. Private incentives have produced social results that are sub-optimal. But as more and more people buy SUVs, the more likely you are to need one in order to make yourself safer should you have an accident with a larger vehicle like an SUV. If everyone drives an SUV, then you will need one, too, and the safety considerations are no longer an issue. Private and social incentives are aligned. This creates an "arms race," as Ms. White calls it, when purchasing cars.

Ms. White suggests some policies that might persuade drivers to consider the impact of their buying decisions on others, including increased liability rules, traffic rules, and insurance

(Updated February, 2004)