Today I want to lift my sights high. So high, in fact, that it takes me to the very top of the income distribution. These are the people who earn many times the average salary, are mainly not Premier League footballers (though they clearly do), and who are endlessly fascinating.

I do so for three reasons. The very well-off, the top 1%, and even more so the top 0.1%, will become even more important as a source of income tax revenues if Boris Johnson carries out his leadership pledge to reduce the tax burden on those slightly lower down the income scale.

That pledge, you may recall, was to increase the threshold at which people pay the higher (40%) rate of income tax from £50,000