The biggest factor determining the performance of an investment portfolio is, according to a landmark paper produced quite a few years ago now, asset allocation.
Asset allocation refers to how much money you put into lower returning safe assets like government bonds versus higher returning risky assets like shares. All investors must consider this issue at some time but there is some disagreement as to what is the right strategy for sovereign wealth funds and other investment entities with ultra long investment horizons. In NZ the NZ Super Fund has a longer investment horizon than most and with almost $20bn in assets it is one of the largest local funds.
The investment experts at the NZSF have determined that an appropriate asset allocation is 80 per cent in growth assets and 20 per cent in bonds - the rationale being that because NZSF has a very long term investment horizon it can afford to take a long term view and have a higher proportion of its money in higher growth, risky assets and in particular assets that are hard to sell and/or hard to price.
These are known as illiquid assets and the theory is that because of the disadvantages of investing in them they will produce higher, more volatile returns. Looking at NZSFs portfolio some 27.5 per cent is in relatively illiquid sectors like infrastructure, timber, property and other private markets. The downside however is cost - it requires expensive experts to manage these sort of assets. Furthermore, to paraphrase George Orwell, some experts are more expert than others.
The strategy of making money out of illiquid assets is popularly known as "harvesting illiquidity premiums" and has also been described as the Swensen model after David Swensen of the Yale University Endowment who did this sort of thing very successfully. We wrote about Mr Swensen's investment success at Yale back in November 19th 2005 in a column entitled "Advice Without The Strings"; but concluded that if we didn't have a genius like Mr Swensen working for us then a complex strategy ran the risk of assuming a high risk, high cost portfolio with uncertain returns.