The 1986 accident at Chernobyl, in which dozens of people died and thousands more were exposed to cancer-causing radiation, created fear and outrage worldwide and led some people to call for the closing of all nuclear plants. Yet many people choose to smoke cigarettes in spite of the fact that 2 million people die every year from smoking-related diseases. The risks posed by nuclear power plants are involuntary—risks that we must all share, like it or not—whereas the risks associated with smoking are largely voluntary because each individual chooses whether to smoke. Why are we so unaccepting of involuntary risk but so accepting of voluntary risk?