The first is convergence: headline inflation has to be on course to reach our aim over a meaningful definition of the medium term. The second is confidence: we need to be sure that this upward adjustment in inflation has a sufficiently high probability of being realised.
In tolerably well-organised economies, simply adding more inputs will lead to more outputs. Certainly, lots of Asians became wealthier, and were able to enjoy rapidly improving material well-being. But there was, in Krugman’s view, no miracle. There was no productivity steroid. The last year or so has generally given strength to Krugman’s analysis.