Paul Krugman, Twit

Paul Krugman reminds us on his blog today that he also has a Twitter account, that he is doing some "direct postings" to it and that, "Some of the tweets are even substantive." I will restrain myself from suggesting that very little that he says anywhere is substantive (well, that restraint didn't last long), but will ask what kind of mind is it that thinks that a "substantive" thought can be expressed in 140 characters or less. I'm thinking that such a position requires a rather trivial mind, but what do I know? I'm not a Nobel economist.