We expect a lot from the middle classes. At least three distinct arguments about the special economic role of the middle class are traditionally made. In one, new entrepreneurs armed with a capacity and a tolerance for delayed gratification emerge from the middle class and create employment and...

During 2006, the Gallup Organization conducted a World Poll that used an identical questionnaire for national samples of adults from 132 countries. I analyze the data on life satisfaction and on health satisfaction and look at their relationships with national income, age, and life-expectancy....