And here is a remark on timing:
I find it astonishing that Krugman and Wren-Lewis, having done post after post in 2012 describing how the UK does have real fiscal austerity in 2012, are suddenly happy to now argue that a relaxation of fiscal austerity in 2012 is the “reason” for GDP recovery in… erm, 2013.
Don’t let the emotionally laden talk of “Three Stooges” or “deeply stupid,” or continuing problems in the UK economy, distract your attention from the fact that this one really has not gone in the directions which the Old Keynesians had been predicting.
This whole set of linked essays is recommended, though I'm finding it challenging to unravel all the logic. Monetary policy is really hard.