comments and suggestions. We review methodological issues that arise in designing, implementing and evaluating the efficacy of 'light ' paternalistic policies. In contrast to traditional 'heavy-handed ' approaches to paternalism, light paternalistic policies aim to enhance individual choice without restricting it. Although light paternalism is a 'growth industry ' in economics, a number of methodological issues that it raises have not been adequately addressed. The first issue is how a particular pattern of behavior should be judged as a mistake, and, relatedly, how the success of paternalistic policies designed to rectify such mistakes should be evaluated – i.e., the welfare criterion that should be used to ju...