The Chinese Exchange Rate and US Borrowing

One cool thing about having my own blog is that I get to comment on Tyler Cowen even when he closes comments. (This is even better than bringing back deleted comments from Brad DeLong’s blog.)

Tyler Cowen argues against pushing for yuan revaluation on the grounds that revaluation would only tie the hands of the US:

The fundamental problem in the U.S., to the extent we have one, is our propensity to spend, especially given our long-run demographic position and our government's fiscal irresponsibility. I don't see how pressuring a more rapid change in one set of relative prices (namely U.S. vs. China), which are likely to change anyway, will cure that ailment in a significant way….

A key reason to be skeptical of yuan revaluation is that it tries to address a relative prices problem by shrinking the opportunity set facing the U.S. That is not obviously the right way to go. The point is not to claim that all elasticities are zero, but rather that a trade balance shift, through revaluation, really does require a loss of resources. What fact about the world would make that the best way to go?

What fact? Two words: sticky prices. Consider the four possibilities:

1. Weak yuan + US borrows


2. Strong yuan + US borrows


3. Weak yuan + US does not borrow


4. Strong yuan + US does not borrow

Which of these possibilities is optimal for the US? Tyler Cowen would probably choose #3, but he’s wrong. Not being a Keynesian, however, he won't appreciate why the correct answer is #4 (although Greg Mankiw should, so maybe he can tell me why I’m wrong).

Why not #3? Because if we choose what’s behind door #3, we get a huge and prolonged recession. A fiscal tightening, in the presence of a still-strong currency, will knock out the economy. (We kind of already tried that one back in 2000-2001. In that case the fiscal tightening came from the business sector, which continues to run a large surplus unto this very day. We have since had a recovery, a slow and painful one, brought about mostly by households and government, which are borrowing heavily, partly from China.) As long as China keeps our trade sector weak by keeping its currency weak, our optimal strategy is to borrow.

Furthermore, as long as the US is willing to borrow, it is in China’s interest (given the conservative preferences of its leaders) to keep its currency weak. If the US suddenly stopped borrowing, it would lower US interest rates and make dollars less attractive relative to yuan, forcing China to absorb incredibly huge numbers of dollars, and ultimately, I suspect, China would give up and let the yuan rise. As it is, the path of least resistance for China is to maintain the peg.

So there are two Nash equilibria, and we are stuck at the bad one. As long as the US borrows, it is optimal for China to peg. As long as China pegs, it is optimal for the US to borrow. Ultimately, both countries would be better off if the US stopped borrowing and China stopped pegging, but, as we say in Boston, you can’t get there from here.

I’m not sure how you get out of this bad equilibrium, but one possible way is by trying to change the preferences of China’s leaders, so that it will no longer be optimal for them to peg. I’m not sure how one goes about that, and Tyler Cowen may be right that political pressure is the wrong way, in which case I’ll concede the war but not the battle.