There is increasing interest in the “economics of happiness”, reflected by the number of articles that are appearing in mainstream economics journals that consider subjective well-being (SWB) and its determinants. This paper provides a detailed review of this literature. It focuses on papers that have been published in economics journals since 1990, as well as some key reviews in psychology and important unpublished working papers. The evidence suggests that poor health, separation, unemployment and lack of social contact are all strongly negatively associated with SWB. However, the review highlights a range of problems in drawing firm conclusions about the causes of SWB; these include some contradictory evidence, concerns over the impact on the findings of potentially unobserved variables and the lack of certainty on the direction of causality. We should be able to address some of these problems as more panel data become available.