Happiness became a mainstay of social science research at some point in the last 20 years. Psychologists, economists, and sociologists descended on the moods and morale of ordinary people, each bringing a characteristic disciplinary focus to the subject. Psychologists and behavioral economists examined happiness as an emotional state. Experiences and relationships bring immediate pleasure or displeasure; data must be collected day to day and even hour to hour (e.g., Diener 1984; Kahneman et al. 2004). Sex and relaxing with friends are the keys to happiness; traffic and talking to the boss wreck one's mood (Krueger and Schkade 2008). Labor and health economists took a longer focus, viewing happiness as the product of separate choices that accumulate good feelings along with goods and services (Easterlin 1995; Kahneman and Deaton 2010). Money, the material satisfactions it buys, and the security that comes from a high income produce an overall sense of happiness; insufficient funds result in both material needs and feelings of insecurity. Sociologists took an even longer view, identifying longstanding relationships with family and friends, worldview (including religion), social class, and lifestyle as sources of life satisfaction or dissatisfaction (Davis 1984; Hout and Greeley 2012; Kohler, Behrman, and Skytthe 2005; Schuessler and Fisher 1985). Both the labor economists and the sociologists relied on self-reported summary measures such as the surprisingly robust simple question, “How happy would you say you are? Would that be very happy, pretty happy, or not too happy?” (Bradburn and Noll 1969) or Cantril's “ladder” (Kahneman and Deaton 2010).

We incline toward the longer view and seek to meld the economic and sociological perspectives. Happiness researchers have found, per expectations, that affluent, married, and religiously active Americans report more happiness, whereas poor, divorced, and secular people report less (Easterlin 1995; Hout and Greeley 2012; Kohler et al. 2005). Dozens of cross-sectional studies replicate the pattern. In 1984, Davis (1984) summarized it as “new money, an old man/lady, and ‘two's company.’” The first element of his formula refers to the pattern, since replicated, whereby recent changes in income boost morale. but people accommodate to new financial circumstances in time. The second element captures the difference between married people and others. The third element refers to his observation that people in two-adult households were happier than those in other living arrangements.