Wearing seat belts and shoulder harnesses is an efficient means of minimizing the costs of automobile
accidents. Assuming that the benefits of these passive restraints exceed their costs, but that not all drivers and passengers
use seat belts, how might the rules of tort liability be changed so as to induce a greater number of people to wear seat belts
and shoulder harnesses?
(pp. 234-35) Three hypotheses might explain the limited use of seat belts. First, the decision to wear a seat belt is a utility-
maximizing decisions made by fully informed, rationally self-interested economic actors. They wear seat belts up to the
point at which the benefits exceed the costs but not beyond. So, whatever they do is optimal (assuming there are no
external effects from the decision about whether to wear seat belts).