CHAPTER 1 THE POWER OF INCENTIVESHow Seat Belts KillMost of economics can be summarized in four words: "People respond to incentives." The rest is commentary."People respond to incentives" sounds innocuous enough, and almost everyone will admit its validity as a general principle. What distinguishes the economist is his insistence on taking the principle seriously at all times.I remember the late 1970s and waiting half an hour to buy a tank of gasoline at a federally controlled price. Virtually all economists agreed that if the price were allowed to rise freely, people would buy less gasoline. Many noneconomists believed otherwise. The economists were fight: When price controls were lifted, the lines disappeared.The economist's faith in the power of incentives serves him well, and he trusts it as a guide in unfamiliar territory. In 1965, Ralph Nader published Unsafe at Any Speed, a book calling attention to various design elements that made cars more dangerous than necessary. The federal government soon responded with a wide range of automobile safety legislation, mandating the use of seat belts, padded dashboards, collapsible steering columns, dual braking systems, and penetration-resistant windshields.Even before the regulations went into effect, any economist could have predicted one of their consequences: The number of auto accidents increased. The reason is that the threat of being killed in an accident is a powerful incentive to drive carefully. But a driver with a seat belt and a padded dashboard faces less of a threat. Because people respond to incentives, drivers are less careful. The result is more accidents.The principle I am applying is precisely the same one that predicted the disappearance of gasoline lines. When the price of gasoline is low, people choose to buy more gasoline. When the price of accidents (e.g., the probability of being killed or the expected medical bill) is low, people choose to have more accidents.You might object that accidents, unlike gasoline, are not in any sense a "good" that people would ever choose to purchase. But speed and recklessness are goods in the sense that people seem to want them. Choosing to drive faster or more recklessly is tantamount to choosing more accidents, at least in a probabilistic sense.An interesting question remains. How big is the effect in question? How many additional accidents were caused by the safety regulations of the 1960s? Here is a striking way to frame the question: The regulations tend to reduce the number of driver deaths by making it easier to survive an accident. At the same time, the regulations tend to increase the number of driver deaths by encouraging reckless behavior Which effect is the greater? Is the net effect of the regulations to decrease or to increase the number of driver deaths?This question cannot be answered by pure logic. One must look at actual numbers. In the middle 1970s, Sam Peltzman of the University of Chicago did just that. He found that the two effects were of approximately equal size and therefore cancelled each other out. There were more accidents and fewer driver deaths per accident, but the total number of driver deaths remained essentially unchanged. An interesting side effect appears to have been an increase in the number of pedestrian deaths; pedestrians, after all, gain no benefit from padded dashboards.I have discovered that when I tell noneconomists about Peltzman's results, they find it almost impossible to believe that people would drive less carefully simply because their cars are safer Economists, who have learned to respect the principle that people respond to incentives, do not have this problem.If you find it hard to believe that people drive less carefully when their cars are safer, consider the proposition that people drive more carefully when their cars are more dangerous. This is, of course,Landsburg, Steven E. is the author of 'Armchair Economist Economics and Everyday Life', published 1995 under ISBN 9780029177761 and ISBN 0029177766.