Is a Cheap Currency Good?

In the comments section of my first post about the euro, reader Keith asks:

1. Isn't it better to have a cheap currency? You get to export more and bring in more money. A cheap currency hurts if you travel outside the country, but on the other hand, you have more money to spend because you export more.
   
   
2. Why has the US followed a strong dollar policy? It seems Japan has had the right idea by keeping their currency cheap.

The simple answer to the first question is that a cheap currency is good for the tradables sector (exports, potential exports, and industries that actually or potentially compete with imports) but bad for the notradables sector (everything else). It’s bad for the nontradables sector because the economy has limited resources, and the additional resources that get used in the tradables sector are no longer available for use in the nontradables sector. For example, China has a cheap currency, and it has thriving export industries, but it has really bad health care, presumably in part because people who could be training to be nurses find it more convenient to take factory jobs in the export sector.

There are any number of problems with the last paragraph. For one thing, Gabriel is probably going to complain about my cavalier use of the words “good” and “bad.” I’m pretty sure that, in a model with nominal rigidities, fixed capital, and search costs, a cheap currency can be shown to have good and bad welfare consequences (respectively) in the short run for people associated with those respective sectors. But I’m also quite sure that the proof would be a pain in the ass, and I expect that somebody (I have no idea who) has already done it, so I’m not going to attempt it. As for the long run, exchange rates are irrelevant because prices and wages adjust completely. (Well, not really irrelevant, because there is path-dependence: what happens in the particular short runs helps determine the long-run equilibrium. But that’s getting too deep for now.)

The second problem is that the phrase “limited resources,” while quite valid, is misleading. Resource limitations are not a simple, tight constraint. There is always some unemployment, and always some idle capacity, so there is always the opportunity to push on resource limitations. The problem is, when unemployment gets too low, or capacity utilization gets too high, then inflation starts to accelerate. And it’s never exactly clear how low is too low and how high is too high. If the country has plentiful slack resources, then a cheap currency is good for everybody. If the country is already overutilizing its resources, a cheap currency could be bad for everybody if it causes an inflationary spiral (but if the central bank is on its toes, this presumably won’t happen).

The third problem is that my China example is not a very good one. (Maybe someone else can think of a better example.) China’s health care problems have more to do with bad insurance markets than with potential nurses becoming factory workers. And China’s construction industry – also part of the nontradables sector – seems to be doing fine. China is quite an interesting case, though, because, on the one hand, it appears to have plenty of slack resources (people working inefficiently in agriculture who can easily take factory jobs) and therefore one might think that there is no disadvantage to a cheap currency. But on the other hand, it is beginning to experience an inflation problem, which would suggest that it is getting the worst disadvantage from a cheap currency. Part of the solution to this paradox, I think, is that China is trying to mobilize its slack resources too quickly and running into bottlenecks. And there’s also the issue of natural resources. I could go on and talk about China’s potentially destabilizing absorption of massive dollar reserves and about China’s possible attempt to exploit path dependence and so on, but I want to get to the second question.

So, why has the US followed a strong dollar policy? And should it? In the late 1990s, I think a strong dollar policy made sense (though Dean Baker disagrees). The reason it made sense is that the nontradables sector in the US was doing a lot of useful things – creating new technologies and investment goods to make US production more efficient in the future – and a weaker dollar would have forced a shift of resources out of the nontradables sector.

Today, though, I don’t think a strong dollar makes any sense, and I think most economists would agree. The economy is weak, and we may be going into a recession, so there are a lot of potential slack resources, and the nontradables sector in recent years has not been doing anything terribly useful with its marginal capacity (mostly building a lot more houses than we really need). That doesn’t necessarily mean, though, that a “strong dollar policy” is a bad idea, if a “strong dollar policy” just means a lot of cheerleading by the Treasury Secretary. I think most economists would agree, what we want is for the dollar to fall slowly, so as not to destabilize markets or cause a bout of inflation. But if investors expect the dollar to fall slowly, they will all sell their dollar assets, and the dollar will fall quickly. The solution, I suppose, is for Hank Paulson to keep saying we like a strong dollar and to convince a gradually decreasing number of suckers that he really means it, so they will wait before selling their dollar assets and prevent a free fall.


[Afterthought: I’m beginning to wonder, though, whether the dollar still is very much overvalued against the euro. It’s getting easy to imagine that, at a dollar/euro exchange rate not too far from the present level, once temporary effects wash out, the Euro Zone and the US could both end up with moderate trade deficits, rather than (as it has been recently) the US having a very large deficit and the Euro Zone having roughly balanced trade. Increasingly, the problem is not an overvalued dollar but undervalued currencies that happen to be pegged to the dollar but that perhaps at this point might almost as well be pegged to the euro.]