I happened to be chatting with an Earth Science prof this morning. He mentioned that enrolment in Earth Science graduate degrees was strongly counter-cyclical (with a short lag). When the job market weakened, more students decided to get a graduate degree. When the job market strengthened, applications for graduate programs dropped.
There seems to be nothing surprising about that. This is ECON 1000 stuff. The main cost of getting a degree is the opportunity cost of lost wages. When you can't get a job, the opportunity cost of getting a degree is low, so more people invest in human capital. And there's presumably nothing special about Earth Science; it's just that mining and exploration fluctuate a lot, so it's easier to see this effect in Earth Science than in other subjects.
But it's very surprising when you compare it to other forms of investment. Business investment is strongly pro-cyclical.
Both human and non-human capital are used to produce goods. Why should investment in human capital be counter-cyclical, and investment in non-human capital be pro-cyclical?
I think there's a simple answer, and that answer tells us something about the nature of the business cycle.
I see the business cycle as a monetary phenomenon. An excess demand for the medium of exchange causes a fall in the volume of monetary exchange. Falls in production and employment are merely side-effects of that reduction in monetary exchange. But barter exchange, and home production, are unaffected by disruptions in monetary exchange. We should in fact see an increase in barter exchange, and an increase in home production, when monetary exchange is disrupted by an excess demand for money, because these are alternative modes of economic organisation.
Investment in human capital is mostly (but not totally) home production. The student's own time is the most important input in the human capital production function. The other inputs that are paid in dollars, like profs and books, are a minor extra.
So investment in human capital will be counter-cyclical, simply because it's (mostly) home production. But most business investment is goods produced by one firm and sold to another firm for dollars. So it's pro-cyclical, because it gets disrupted by the same disruption to monetary exchange that we call "recessions".
There are probably exceptions that prove the rule. My guess is that DIY home renovations by handy Red Green types may be countercyclical too. (New home construction is an intermediate case, because we buy new homes with dollars, but we often rent them to ourselves with no dollars flowing from our right pocket to our left pocket.)
The business cycle is not a saving and investment thing. The business cycle is a monetary exchange thing.