Normally, economists do not measure the antics of spies. But these are not entirely normal times; or not as far as the American business community and US Department of Justice is concerned.

In recent months, the DoJ has pursued cases where American officials think that spies for China have been stealing commercial secrets from American companies. This year, for example, the FBI apprehended Allen Ho, an American national born in Taiwan, and accused him of stealing nuclear technology for the state-owned China General Nuclear Power Group (CGN has stirred up controversy because it is one of the investors in the planned UK nuclear power plant at Hinkley Point).

Separately, the DoJ and FBI have accused Chinese-born nationals of stealing know-how from advanced underwater vehicle technology to military-grade carbon fibre. They have even chased spies who tried to steal the technique for using titanium dioxide to make consumer goods appear ultra-white; this technology, owned by DuPont, is used for items ranging from the filling in Oreo biscuits to tennis court lines.