Look just about anywhere in the emerging world, and real exchange rates have appreciated rapidly over the past 12 months. Brazil's real is up 27 per cent, Russia's rouble 14 per cent and the Bloomberg-JP Morgan Asia Dollar index, which tracks the 10 most active emerging Asian currencies, is at a 19-month high.

This is due to a “capital bonanza” in emerging markets, driven partly by ultra-low interest rates in the developed world and rising interest rates elsewhere.

But it also follows a fundamental reassessment of the creditworthiness and prospects of emerging, versus developed, economies. The result for the developing world is a possible capital surfeit and attendant fears of overvalued exchange rates, floods of cheap imports and extreme volatility should the wall of money eventually retreat.