SINCE the US subprime crisis of 2008, global growth has come largely through large-scale cash injections by developed countries' central banks led by the US Federal Reserve.

Although the effect of these actions has been positive in that they have probably helped stave off a depression, they have also proven to be a double-edged sword - by lowering the return on sovereign bonds and by keeping interest rates artificially depressed at near-zero, economies may have stabilised but investors have been simultaneously forced to seek yield in markets for higher-risk assets such as equities and lower-rated bonds.

This has led to what some consider huge bubbles in risky assets and increasing worry as to how a global financial system grown reliant on cash injections might cope if these bubbles burst. Last week, for instance, the International Monetary Fund (IMF) issued its second warning in six months about intensifying risks in the global financial system.