This is a fascinating discussion by Bruce Greenwald of

1. the difficulties of shifting people from working in sectors like agriculture and manufacturing where employment is declining because productivity is going up faster than demand,

2. the efforts of some countries to export this problem to other countries, and

3. the effect of these forces on interest rates, and therefore, implicitly, their interaction with the zero lower bound.

It is very interesting to think about how these issues could play out if there had been no zero lower bound and their had been aggressive negative interest rate policy. Regardless of the low interest rates, it still doesn’t work to have more manufacturing output that people want to buy any more than it makes sense to have more food grown than people can possibly eat. So at the end of the day, manufacturing capacity would get high enough to put a brake on further investment in manufacturing despite very low interest rates. Either people will start consuming a lot more because of the low interest rates, or more likely there would end up being extra investment in something else. A good possibility is education. Education is a form of investment that can easily absorb a huge amount of resources simply in student time, even if in the future it doesn’t need much in the way of buildings or professors because it has gone electronic. Standard human capital theory suggests that a low enough long-run real interest rate can have a big effect on the amount of education chosen.