You don’t often see me mention Paul Krugman twice in one week, but. . .

There are still some reasons to wonder whether the economy has really turned the corner.

First, while there was a significant pickup in business investment, the bulk of last quarter’s growth came from a huge surge in consumer spending, with a further boost from housing. These components of spending stayed strong even when the economy was weak, so there shouldn’t have been any pent-up demand. Yet housing grew at a 20 percent rate, while spending on consumer durables (that’s stuff like cars and TV sets)