In the 20th century, Americans, Europeans, and East Asians enjoyed material and technological advances that were unimaginable in previous eras. In the United States, for instance, gross domestic product per capita tripled from 1950 to 2000. Life expectancy soared. The benefits of capitalism spread more widely among the population. The boom in productivity after World War II made goods better and cheaper at the same time. Things that were once luxu­ries, such as jet travel and long-distance phone calls, became necessities. And even though Americans seemed to work extraordinarily hard (at least compared to Europeans), their avid pursuit of entertainment turned media and leisure into multibillion-dollar industries.

By most standards, then, you'd have to say that Americans are better off now than they were in the middle of the last century. Oddly, though, if you ask Americans how happy they are, you find that theyre no happier than they were in 1946 (which is when formal surveys of happiness started). In fact, the percentage of people who say theyre very happy has fallen slightly since the early 1970s -- even though the income of people born in 1940 has increased, on average, 116 percent over the course of their working lives. Nor is this a uniquely American phenomenon: you can find similar data for most developed countries. Perhaps the most striking example of progress having little impact on what economists call people's sense of subjective well-­being is Japan. Between 1960 and the late 1980s, Japan's economy was utterly transformed, as the nation went from a low-cost supplier of cheap manufactured goods to what is perhaps the worlds most technologically sophisticated society. Over that stretch, the country's GDP quintupled. And yet by the late 1980s, the Japanese said they were no happier than they had been in 1960.