Investigations of historic yields are therefore mostly concerned with homo- genous goods such as commodities, for which indices are available. These show that certain real assets can achieve higher yields than investments in equities or bonds. A comparison of the average historic yields on raw materials over the last 10 years (2002 to 2012) shows that investments in commodity futures have achieved double-digit annual returns (see Fig. 15). This consider- ation of averages over a long period however hides the fact that the profitability of individual investment vehicles naturally depends on the time the investment is made. For example, investors in aluminium.
