Wednesday, November 11, 2009
Are Football Hemets Risky?
An article in today's WSJ raises an interesting question about head safety. Concussions are common among pro football players, and retirees often experience head and brain issues later on in life. Would they be better off without helmets? Obviously, no helmets would change the game. When I was in graduate school, a classmate thought about doing his dissertation on whether safer football equipment actually reduced injuries. His expectation was no--as the equipment gets better, the behavior of the players changes. This fits into a well-known article written by Sam Peltzman concerning automobile safety mandates and whether they resulted in saved lives. Peltzman hypothesized that as people drove safer cars, their driving behavior would change. People would drive less defensively. The probability of dying in a car accident is the probability of being in an accident times the probablity of death given you were in an accident. Safer cars--mandatory seat belts, collapsable steering columns and so on, reduce the probability of death given an accident. But changed driving behavior may increase the probability of an accident. Peltzman's empirical analysis found that few drivers and passengers in cars died but more pedestrians and motorcycle riders died. This is consistent with the behavior change. (See Sam Peltzman, "The Effects of Automobile Safety Regulation," JOURNAL OF POLITICAL ECONOMY, 1975, 83 (4), pp. 677-726).