Moral hazard is easy to justify theoretically but difficult to detect empirically. Individuals may report sick due to illness as well as for moral hazard reasons. Potential abuse of the sickness insurance system in Sweden is estimated by comparing the change between the number of men and women who report sick during a popular sporting event and a preceding time period. Difference-in-differences estimates provide clear evidence that the number of men who reported sick increased in order to watch the sporting event on television. Copyright © 2004 John Wiley & Sons, Ltd.