But it is hard to apply to Germany, where unit Labour costs have been held down for a decade and where, if the economy does need to be rebalanced, it is arguably in favour of consumption.

Over the past decade, European firms have been much more successful than America in holding down unit labour costs and thus remaining competitive.

China and India announced plans in recent days to reduce the energy intensity, or the amount of carbon-dioxide emissions per unit of gross domestic product, of their economies over the next decade.