These various schemes may help the cyclically unemployed find work and, in so far as those people would have become permanently unemployed, help reduce structural unemployment too.

It is certainly hard to spot bubbles; but central Banks already grapple with other imponderables, such as the size of the output gap or the level of structural unemployment.

Yet that's what you hear from many pundits these days: high unemployment is "structural," they say, and requires long-term solutions (which means, in practice, doing nothing).