National accounts of subjective well-being are being considered and adopted by nations. In order to be useful for policy deliberations, the measures of life satisfaction must be psychometrically sound. The reliability, validity, and sensitivity to change of life satisfaction measures are reviewed. The scales are stable under unchanging conditions, but are sensitive to changes in circumstances in people's lives. Several types of data indicate that the scales validly reflect the quality of respondents' lives: (1) Differences between nations in life satisfaction associated with differences in objective conditions, (2) Differences between groups who live in different circumstances, (3) Correlations with nonself-report measures of life satisfaction, (4) Genetic and physiological associations with life satisfaction, (5) Systematic patterns of change in the scales before, during, and after significant life events, and (6) Prediction by life satisfaction scores of future behaviors such as suicide. The life satisfaction scales can be influenced by factors such as question order, current mood, and mode of presentation, but in most cases these can be controlled. Our model of life satisfaction judgments points to the importance of attention, values, standards, and top-down effects. Although the scales are useful in research on individual well-being, there are policy questions that need more analysis and research, such as which types of subjective well-being measures are most relevant to which types of policies, how standards influence scores, and how best to associate the scores with current policy deliberations.