The increased percentage of persons who go to college is not surprising. Advances in technology have reduced the demand for brawn and increased the demand for brains. But several significant questions (concerning college education in the United States, to which I confine this comment) remain:
The first is why female college enrollment has increased so much faster than male college enrollment, and why female college students do much better, as measured by grades and graduation rate, than male. If college is more valuable to a woman in the labor market than to a housewife, then as more women work relative to engaging in full-time household production, women's demand for a college education will rise; apparently this factor has dominated the effect of advances in technology on both sexes, for otherwise their rates of enrollment would be growing at the same rate. Of course technology, in the form of labor-saving household appliances, more reliable contraception (including abortion), the higher ratio of light to heavy work, and reductions in infant mortality (a factor in limiting the size of families) may underlie the increase in women‚Äôs participation in the labor market. But only the increase in the ratio of light to heavy work is a change in the technology of work that favors women by reducing the demand for brawn and hence for male labor relative to female.
But why are proportionately more women going to college and, once there, outperforming the male students? One answer may be that they get more out of college than men do. Maybe they gravitate to fields in which college learning is more valuable than it is in the fields that men gravitate to. Suppose that men have a comparative advantage (as they probably do) in jobs that involve danger, disagreeable working conditions, upper-body strength (of course), and financial risk. Those are jobs to which going to college, or in some instances (such as financial risk taking) concentrating once there on academic performance, may not contribute a great deal.
Another question is whether college attendance or graduation is the right variable for estimating the returns to education. Suppose that high schools deteriorate; that would increase the demand for college, especially for community colleges that may offer a level of teaching no different from that of a good high school. Most high schools are public and do not compete for students. The college market is far more competitive. A community college may offer a superior high school education.
And finally, how much more will college attendance increase? Will it go to 100 percent (currently, about 60 percent of high school graduates go on to college--of course many kids drop out of high school)? That depends on two factors: the brain/brawn tradeoff, and IQ (or some alternative measure of intellectual aptitude). If the intellectual demands of work relative to the physical demands continue to increase, the demand for college will also increase. IQ is, though, a limiting factor. But it is less of a limiting factor than one might think. The reason is that a frequent byproduct of technological advance is deskilling. Fifty years ago, a driver had to know how to change a tire and put chains on a tire, how to check the engine's oil level and the water level in the radiator, and how to start a car in freezing weather. These skills are no longer required. Most cashiers no longer need to know how to make change; the cash register tells them how much change to give the customer. Printers no longer need to know how to set type upside down. With advances in neuroscience, artificial intelligence, computer science, robotics, and nanotechnology, many jobs that require a college education today will require little in the way of education tomorrow. Many people may then defer college until retirement, in order to increase the returns to leisure by widening their cultural horizons.