To adapt the exchange between Ernest Hemingway and his literary agent: the super-rich are very different from the rich. They have even more money.
Much of the traditional analysis of inequality focuses on the relationship between those towards the middle and those towards the top of the income range. But in recent years the most dramatic widening, at least in the US, has been between the very top and everyone else.
The share of income claimed by the top 1 per cent of American earners declined after the Great Depression and the second world war, but from the late 1970s it suddenly started to rise. Meanwhile, wage growth for many in the middle has stalled.