The risk of the rising yen, notes Frederic Neumann, HSBC's senior Asia economist, is that any benefit in consumers' purchasing power is far outweighed by the negative effects on the export economy.

If you're willing to cross a busy street to pick up a? 20 note, the economist who put it there can infer something about your willingness to accept risk.

Dong Xian 'an, economist with China Southwest Securities, said: "For many exporters, the dollar's fluctuation is a serious concern."The ability to settle trade in the yuan would reduce such risk.