Birthrate crisis would require a whole new mindset on growth | Larry Elliott

If forecasts are wrong, developed countries will need to rethink immigration, healthcare and pensions

It was Europe's deadliest ever import. A particularly virulent form of the bubonic plague travelled westwards from China across the steppes of Asia and ended up at Black Sea ports. As far as can be established, rats carrying diseased fleas were on ships that set sail from the Crimea to Mediterranean ports. Between 1348 and 1350, the Black Death killed at least a third of Europe's population, with mortality rates as high as 60% in some parts of the continent.

Europe has not since witnessed anything remotely like the depopulation of the mid-14th century. It took hundreds of years in some regions for the population to regain its pre-Black Death level and the economic effects were profound. A shortage of labour meant wages went up. Land was left untilled and fell in price. The gap between landowners and workers narrowed. Incentives to develop labour-saving devices meant productivity rose.