You can hear the screams almost from S?o Paulo to Tokyo. Data are notoriously unreliable for currencies, but you can bet your bottom dollar that more than the average number of punters are copping a loss from the latest gyrations in foreign exchange markets. It is not as though this pain is the result of a return to some benign exchange rate equilibrium. Indeed, the latest bout of exchange rate turmoil could accentuate the problems facing the global economy.

Some currencies were certainly out of alignment. The Australian dollar, which has fallen 6 cents against the US dollar in the past five days, had attached itself to the China story and was too high for anyone’s good. Likewise, the Swiss franc has reached ridiculous levels on the basis that it is neither the dollar nor the euro, while the strong yen was so painful that Japan intervened to try to bring it under control.

Yet the long-term trend of strong emerging market currencies versus developed ones is exactly what the global economy requires. Recent reversals, if sustained, would be unhelpful. For example, if the US is to have any chance of lower fiscal deficits without company profits disappearing, it requires an improvement in the current account of about 10 per cent of gross domestic product, Smithers and Co estimates. And the only hope of achieving that is through a real fall in the dollar versus fast-growing emerging nations.