The economics of happiness is applied to further the understanding of important consumption decisions in which limited willpower is often argued to lead to suboptimal choices. Based on individuals' judgments of the quality of their lives, it is, in principle, possible to derive whether some observed behavior is suboptimal and is therefore reducing a person's welfare. We discuss the key characteristics and the normative basis of the approach including the evaluation metric and issues of empirical identification. In addition, evidence on willpower and subjective well-being for three important domains of consumption is presented, i.e., TV viewing, smoking and eating.