Alan Layng, a co-conspirator, sent Guido this neat piece of research* :-
I took UK stock market performance since 1902 assuming reinvested income and adjusting down for cost of living to give real terms equity market growth for each of the last 106 years.
I matched this up to the dates of each of the twenty prime ministers who have run this country since 1902 (interpolating to the right dates as required). This gave me a proxy for how much the equity markets had risen (or not) under their stewardship.
From there, it is a small hop to a comparable figure – compound annual growth rates – and, hey presto, we can compare the financial performance of each of prime ministers, and also of the parties, to see if one party has a better long term track record.
It makes interesting reading.