Welfare and well-being have traditionally been gauged by using income and employment statistics, life expectancy, and other objective measures. The Economics of Happiness, which is based on people’s reports of how their lives are going, provides a complementary yet radically different approach to studying human well-being. Typically, subjective well-being measures include positive and negative feelings (e.g., momentary experiences of happiness or stress), life evaluations (e.g., life satisfaction), and feelings of having a life purpose. Both businesses and policymakers now increasingly make decisions and craft policies based on such measures. This chapter provides an overview of the Happiness Economics approach and outlines the promises and pitfalls of subjective well-being measures.