Apart from low productivity growth, of course. That is the topic of my latest Bloomberg column. Wages have been sluggish throughout the recovery, profits on capital seem to be high, there is a domestic investment drought, and the onset of the internet and globalization make many of the “monopolization” charges less than plausible. Here is one possible route of inquiry:
Capital today can cross borders more easily than it could a few generations ago. That might keep real wages down in the U.S. If wages threaten to rise during an economic recovery, for instance, it is then profitable to invest more capital abroad, where wages usually are lower. The end result resembles what economists call a “Malthusian” equilibrium. That means there is an upper limit to returns to labor: They cannot exceed the cost of bringing more labor to market, for instance by investing abroad (or perhaps building robots). Even a long recovery won’t help wages rise above that limit.
This same hypothesis can help explain both the U.S. investment drought and supercharged growth in many emerging economies. If capital is flowing overseas, that will boost growth abroad and worsen a shortfall of investment at home. Too much foreign capital flowing into the U.S. is absorbed by Treasury securities, rather than the private sector.
What about the high rates of return measured for capital investment in the U.S.? It seems strange to have high profits but low investment. Why not invest more to earn more money, thereby leading to an investment glut until the profits are competed away?
One hypothesis is that investors now expect a higher rate of return for domestic investments, a possibility suggested by economists Loukas Karabarbounis and Brent Neiman in a recent paper. Let’s say that entrepreneurs used to be willing to make domestic investments for an expected 7 percent return but now they demand at least 10 percent.
Entrepreneurs will cut back on investment, but the remaining projects will have higher returns on average, more closely bunched around 10 percent than 7.
What accounts for this increased reluctance? Karabarbounis and Neiman consider factors such as greater risk aversion. A simpler alternative explanation, consistent with my capital mobility hypothesis, is that newly available rates of return in other countries are high, and that means competing investments in the U.S. will need to offer higher returns too.
Do read the whole thing, I also consider potential flaws in the argument, such as capital possibly not being mobile enough.