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Is today’s stock market tumble a sign of concern over the national debt? Paul Krugman says no:

The “signature” of debt concerns should be stock and bond prices both falling; what we actually see is those prices moving in opposite directions. And that’s normally the signature of concerns about a weak economy and deflation risk (see Japan, decline of).

What triggered economy fears? To some extent I think this is a Wile E. Coyote moment, with investors suddenly noticing just how weak the fundamentals are. Also, the mess in Europe.

And maybe, maybe there is an S&P story — but not the one you think. Arguably, that downgrade will bully policy makers into even more deflationary, contractionary policies than they would have undertaken otherwise, which has the perverse effect of making US debt more attractive, since the alternatives are worse.

But all the Very Serious People, having totally misdiagnosed our problems so far, will probably double down on that wrong diagnosis as markets fall.