"Productivity isn't everything, but in the long run it is almost everything." So said Paul Krugman, the Princeton economics professor and New York Times columnist, long before he took up journalism. His words are regarded almost as a truism today.

Faster growth of labour productivity - the amount of output or gross domestic product from every hour worked - allows economies to expand faster without stoking inflation, raises living standards or allows countries to choose to work less without suffering lower income. Almost every politician promises to increase the rate of productivity growth on being elected; few achieve success.