In his speech, Mr Carney said it might make more sense in today's circumstances to target not the growth of prices (inflation) but the growth in the cash value of economic output: nominal GDP.

BBC: A new target for the Bank of England?

To start with probably the least important aspect of all this, I am surprised by how little emotion has been sparked by Mr Carney's remarks, that there might be a case for replacing narrow inflation as a target with nominal GDP target, or the cash value of annual economic output.

BBC: Can the Bank of England hit any target?

But that is a lame excuse: it should be much easier to count bodies than to put a value on diverse sorts of economic output.

ECONOMIST: Economics focus

The total value of Japan's economic output measured in yen did not increase at all between 1991 and 2011, because increases in the volume of output during the two decade period were entirely offset by falling prices.

BBC: Q&A: Bank of Japan's inflation target

It has adjusted UK gross value added, a measure of economic output, to exclude energy extraction and use, and also financial and insurance activities.

BBC: How pretty is the UK without the "bad bits"?

In other words, just the dollar version of Libor sets the price for deals with a notional value equal to nine times global economic output or GDP.

BBC: Barclays 'attempted to manipulate interest rates'

The government wants these "high value" sectors to account for about 15% of economic output, or GDP, by 2020.

BBC: Remember the "Green economy"?