Roughly matching the one billion people living in extreme poverty, there are about a billion living at a level of affluence never previously known except in the courts of kings and nobles. As King of France, Louis XIV, the “sun king” could afford to build the most magnificent palace Europe had ever seen, but he could not keep it cool in summer as effectively as most middle-class people in industrialized nations can keep their homes cool today.

But we’re not just better off than a French King who lived centuries ago. We are also much better off than our own great-grandparents. For a start, we can expect to live about thirty years longer, in part because a century ago, one child in ten died in infancy. Now in most rich nations that figure is less than one in 200. Another telling indicator of how wealthy we are today is the modest number of hours we must work to meet our basic dietary needs. Today Americans spend, on average, only 6 per cent of their income on buying food.