Thomas Piketty is of course the French economist who shot to fame, somewhat improbably, on the back of an 800-page tub thumper Capital in the Twenty-First Century, published in 2013. Notwithstanding the exorbitant length of the book, one that defeated all but determined professional readers, the message was handily clear. While economic growth is making societies richer, they are also becoming more unequal. This growing inequality is not the result of the rich working harder or longer, but because passive income, or 'rents' earned from land and patents, is far outstripping growth in salaries. Moreover, since these rents can be passed on down the generations, wealth and privilege encrusts itself in the hands of the few, irrespective of talent, merit, or ability.