The combination of low unemployment and weak wage growth might qualify as one, but I think low productivity growth can explain quite a bit of that particular puzzle. We’ve had only limited data since productivity flattened out, a few years ago, and if you estimate a Phillips curve only over that period the resulting estimates are bound to be imprecise. But, to my mind, the basic judgement in the MPC’s forecast – that, for given productivity growth, less slack leads to faster wage growth – still looks reasonable. 11  Some people came back to me claiming this wasn’t a word. It is. Those readers who’ve got this far deserve some light relief. Thanks to the wonders of technology I found a long list of “imponderables” on the internet, compiled by an engineer in New Mexico – see http://www.unm.edu/~jerome/imponder.htm. I don’t know that these are any more or less insoluble than the impact of Brexit on interest rates, but they’re certainly (at least) as entertaining. 13  All speeches are available online at www.bankofengland.co.uk/speeches  13  The effects of Brexit on inflation, and ultimately on the appropriate level of interest rates, are altogether more uncertain and more complex. They’re certainly too complex to justify the simple assertion that Brexit necessarily implies low interest rates. The MPC eased policy in August 2016 not because of the referendum result but because of the steep fall in measures of business and consumer confidence that followed it.
As supervisors we do not think in terms of countries, but of banks’ business and risk profiles. Each bank operates differently and therefore has to face different problems; it would be unwise not to see them individually. BIS central bankers’ speeches  3