The sudden fall in China’s currency last week spurred a lively debate about whether the move was a victory for market reform or a competitive devaluation designed to shore up flagging exports. But even those who believe the 3 per cent drop was aimed at exporters acknowledge that a weaker renminbi by itself is radically insufficient to cope with the challenges facing China’s economy. “Currency depreciation to stimulate export growth is neither useful nor necessary,” said Qu Hongbin, HSBC chief China economist. He notes that while China’s exports have fallen this year, “exporters across Asia faced the same challenge, suggesting that the underlying problem is sluggish demand in developed markets”. China’s economy officially grew at an annual rate of 7 per cent during the first half of this year, neatly in line with the government’s full-year target. However, some doubt that figure — Capital Economics, for example, reckons it is 5-6 per cent — and there are widespread suggestions that further stimulus will be needed to prevent a slowdown.