THE post-war generation of baby boomers—those born between 1946 and 1964—have had a huge impact on the world, creating "youth culture", changing social attitudes from the sixties onwards, boosting economic growth as they entered the workforce and so on. Now they are starting to retire and this blog has banged on about the effect this will have on issues like pensions, asset markets and economic growth. Not to worry, say some folks, because although we may have more elderly to look after, we will have fewer children.

Alas, that won't help, as this graph compiled by statistician Simon Hedlin shows. The total dependency ratio (children and retirees, compared with those of working age) fell in all G20/OECD nations bar Germany and Sweden between 1960 and 2010. In the next 50 years it will rise in all those nations, bar India and South Africa. In most nations, the ratio will rise by 40% or more; there are huge increases in dependency in parts of Asia (China and South Korea) and in eastern Europe. Britain and America are towards the bottom of the table, but their problems are big enough.

There are many implications. With more dependants to care for, it is very hard to imagine how we will pay down our debts. And it is also very hard to imagine how one can possibly expect government spending to shrink significantly.