At his annual news conference in March, Wen Jiabao, China’s usually dour premier, promiseddismissed calls for revaluation of the renminbi as ill-considered - but then warned mischievously that any revaluation of his country’s currency would come as a surprise to the markets.

Mr Wen’s efforts were only half-partly successful, however. China’s move to a more flexible exchange rate has been in the works for so long, and the revaluation itself was so small - just 2.1 per cent against the US dollar - that it caused little shock when it came on Thursday evening in Beijing.