Commodities: This Time It's Different by Krugman

Now, what about food prices?

Not much evidence of hoarding, as far as I can tell. So this is straightforward supply and demand. Demand may be up to some extent because of that emerging-market boom. But if you look at the FAO reports it becomes clear that the key thing for cereals prices is that production is down in advanced countries, largely owing to terrible weather. And yes, it’s likely that climate change has played a role.

Oh, and what about Ben Bernanke? Well, to the extent that emerging markets are insisting on a fixed exchange rate against the dollar in the face of obvious overvaluation, that contributes to the boom and hence to demand. But I don’t think it’s reasonable to demand that the Fed stop fighting US unemployment in order to keep Chinese currency manipulation from leading to cotton hoarding by Chinese farmers.

So the story on commodity prices is somewhat different from the story during the last spike. As always, though, it’s crucial to keep your eye on the bale -- that is, whatever your logic, it must translate into actions that affect the physical supply and demand for raw materials.