The source:  “A Century of Work and Leisure” by Valerie A. Ramey and Neville Francis, as summarized in The NBER Digest, Feb. ­2007.

The British economist John Maynard Keynes predicted in 1930 that the central problem of humanity in the future would be how to spend its copious leisure time in a meaningful way. He saw productivity increasing so dramatically that companies would have to dole out work sparingly to have enough to go around. Although Keynes was correct about productivity and, to some extent, the shrinkage of the work­week, he was out to lunch on ­leis­ure.

Studies show that Americans work hundreds of hours less per year than they did a century ago, potentially opening up vast new opportunities for leisure activities. But measurements of work and leisure depend on who and what are counted. Unlike earlier researchers, Valerie A. Ramey and Neville Francis, of the University of California, San Diego, and the University of North Carolina, Chapel Hill, respectively, include everybody, young and old, in their study of leisure time, because the definition of “working age” has changed so much over the past 100 years. And they define leisure differently as well, toting up only activities that people enjoy, not taking the car to be inspected or sending off payments to the utility ­company.

True leisure time available to Americans, they write, remains almost the same per capita as it was in 1900. The number of paid ­on-­the-­job hours has declined, to be sure. What has expanded most is the amount of time spent in education. High school is now required, and more than half of high school graduates enroll in college. The authors conclude that about 70 percent of the decline in hours worked has been offset by an increase in hours spent in school (which are counted as work).

Moreover, despite the proliferation of labor-saving appliances, to say nothing of the relatively recent arrival of takeout food, “home production” ­work—­tasks such as cooking, cleaning, grocery shop­ping, commuting, and yard ­work—­grew over the century. It increased partly because standards rose. In 1913, a home economist observed that “if one is poor it follows as a matter of course that one is dirty.” As America got wealthier, expectations of cleanliness went up, and laundry, dish­washing, and housecleaning took more time. As breadwinners got better jobs, families bought more food and acquired fancier tastes, which required more and higher-quality cooking. As families had fewer children, more time and effort had to be put into the nurture of each ­one.

The researchers extracted their definition of leisure from a survey rating enjoyment of various activities. The activities with the highest scores were counted as leisure, and among them were sex, sports, playing with the kids, movies, and sleep. The losers on the enjoyment scale were counted as home production ­work—­commuting, babysitting, home repair, gardening, and ­laundry.

The authors acknowledge a “degree of imprecision” in their estimates, but they believe that, overall, they have accurately captured the direction of change in true leisure time between 1900 and 2000: It went ­nowhere.