How does the spending power of the new pound coin compare to that of the old threepenny bit, last minted in 1970?
The intervening 47 have been a period of almost unrelenting economic liberalisation.
There were very brief and only partial exceptions under Harold Wilson during his swansong, and under Gordon Brown after the Crash.
But Ted Heath did far more of it than his friends and his enemies alike would care to admit, with catastrophically stagflationary consequences.
We all know about the rest of them.
And what has been the result?
From three old pence to one pound is inflation of eight thousand per cent.