Education as a tragedy of the commons
The New York Times is discussing whether we spend too much on education, or not enough. It might help to phrase the question more explicitly, either as:
1) Would individual families benefit from investing more in their own education?
2) Would society as a whole benefit from investing more in education?
Two commentators point out that individuals with more education have substantially higher salaries, on average. Maybe those individuals would have had higher salaries even if they hadn't gone to college, of course, or even if they'd gone to a less-expensive college. That question has been debated elsewhere, and I don't have anything to add.
But even if college is a good investment for individuals, it isn't necessarily true that we would be better off, collectively, if we spent more, collectively, on education. Assume, for the sake of argument, that the number of high-paid jobs is fixed at 10% of the working-age population. If those with more education are more likely to get those jobs, then investing in education makes sense for individuals and their families.
Education could be a sound individual investment even if the education itself was worthless and incomes were determined only by credentials relative to others. But, if producing more people who are qualified to be medical doctors doesn't increase the number of jobs for doctors, then the higher pay of college-educated doctors relative to less-educated nondoctors doesn't make educating more people a good investment for society as a whole.
Individual benefits from investing in education don't necessarily translate into societal benefits from investing in education.
How might society benefit if more people were more educated? My guess is that, if more people were better educated, we would have less crime, a stronger economy, and better political decision-making. My guess is that these societal benefits would outweigh the societal costs of investing more in education. But you can't estimate the total return on these societal investments from the economic return to individuals from investing in their own education. Societal benefit:cost ratios could be lower or higher than those for individuals.
Here's another important point. The return on investments in one kind of education for one group doesn't necessarily predict the return on investments in other kinds of education for other groups. Years ago I saw a comparison of countries that started with similar economies and invested similar amounts of public money either in universities or in primary education. Investing in primary education led to lower birth rates, so the education budget was spread among fewer kids. They developed educated workforces and their economies grew, so that eventually they could afford universities as well. (Until then, citizens wanting more education got it in other countries, thereby making contacts that improved trade.) In contrast, the countries that focused on universities only educated -- "credentialed" might be a better word -- the children of the ruling kleptocracy. The overall population stayed ignorant, birth rates stayed high, and economies stagnated.
Fortunately, I live in a rich country that can afford both great universities and great primary and secondary schools. An honest cost:benefit analysis would be a good place to start.