China’s stealth fighters have prompted cries of alarm in the US. As the White House prepared for last week’s meeting between US and Chinese leaders, China’s rapid economic expansion was also causing angst. Arvind Subramanian at the Peterson Institute for International Economics calculated China passed the US to become the world’s biggest economy last year, when adjusted for purchasing power.

Many economists will dispute Mr Subramanian’s calculations (he rejects the standard measures of purchasing power parity). Even in simple dollar terms, though, figures last week showed China passed Japan to become the second biggest economy.

The economic consensus believes China will keep on expanding, to surpass the US in dollar terms some time in the next 40 years. In short, China matters.