Paul Krugman is still upset over the decision by Switzerland's central bank to end its peg to the euro and allow the value of the Swiss franc to rise. Since some of us non-hyper-inflation worriers don't share his anger, perhaps it worth explaining the difference in views.

Krugman sees the peg as a sort of quantitative easing. He argues it was working (Switzerland's economy has largely recovered), so there was no reason to abandon it. He sees the basis for abandonment as a needless fear over inflation and possibly a concern about central bank losses. (The Swiss central bank is partly private. Sound familiar?)

Krugman may well be right about the reasons that Switzerland's central bank abandoned its peg, but that doesn't mean that it was wrong to do so.

Switzerland's peg was designed to promote its growth at the expense of its neighbors. The under-valued currency boosts the economy by making Swiss exports cheaper relative to the goods and services of its trading partners and making imports into Switzerland more expensive. In this story, Switzerland's growth is a direct subtraction from the growth of its trading partners.

This is not a big deal with a relatively small country like Switzerland, but imagine that Germany left the euro (hold the applause) and adopted the same policy of deliberately under-valuing the new mark against the euro. Germany would then run large trade surpluses and the other euro zone countries would run large deficits, draining away demand. Should we applaud this policy as a form of quantitative easing that needs to be supported?

Krugman's argument rests largely on the idea that we need to promote central bank credibility. I'm a bit more skeptical on this one. Central bank credibility is a two-edged sword. One of the main reasons that we are not supposed to pursue QE-type policies is the risk of inflation, which could undermine central bank credibility.

I would agree with Krugman that the risk of any serious outburst of inflation in the current economic situation is near zero, but of course it is not zero. And the risk of inflation in an economy with less demand and higher unemployment is lower than the risk in an economy with more demand and lower unemployment. This means that we do face more of a risk of inflation and damaging central bank credibility on keeping inflation low with QE than without.

For me, this is a no-brainer. How many parents of children should be unemployed so that everyone knows the Fed won't let the inflation rate get above 2.0? The answer would be very few, but if central bank credibility is some great good of enormous value, then the QE-foes may have a point.

I would keep credibility on the back burner here. Switzerland has a budget surplus and extremely low government debt. It should be running budget deficits to boost its economy and those of its neighbors. There is no reason we should be applauding its efforts to sustain demand in its economy at the expense of its neighbors.