American living standards improved considerably between 1900 and 2000. While most observers focus on gains in per-capita income as a measure of economic well-being, economists have used other measures of well-being: height, weight, and longevity. The increased amount of leisure time per week and across people's lifetimes, however, has been an unsung aspect of the improved standard of living in America. In Century of the Leisured Masses, David...