With the sharp falls in commodities prices in the second half of 2008, investors are questioning the concept of the commodity super cycle and the rationale for investing in that asset class.

Indeed, this year's 15 per cent rally in commodities is being ascribed to temporary factors, including speculative short covering and stockpiling in China. Last year's near 40 per cent pullback in commodities, though, should be viewed as a healthy correction in a secular commodity bull market. Indeed, there are three reasons for expecting commodities to perform well over coming years.