Undercover Economist

Pick a fund, any fund…

Most active managers do not manage to outperform passive funds – particularly not when their fees are deducted

The supermarket checkout poses a frustrating puzzle. Which line to choose? The one with fewest people? Pah! An amateur’s mistake. One must first look at the number of goods in each shopping trolley to get a sense of how long each person in the queue will take. Elevating the analysis a little further, consider awkward items such as crisps (hard to read the barcode), fruit and vegetables (which must be weighed), alcohol (requiring proof of age). A still higher form of thought is to evaluate the shoppers themselves. Will they fiddle for change? Pull out a cheque book or a wad of coupons and vouchers? If so, avoid.

Yet expending all this mental energy is the mark of a mediocre mind. The truly sophisticated thinker – an economist, for example – knows that there is no need to waste effort. Since others are keenly searching for the shortest queue, there won’t be a shortest queue at all. Each opportunity will immediately be filled, and each line will on average take the same amount of time. Pick a queue at random. Any will do, for they are all much the same.

This is also the case for passive investment. Why spend time carefully choosing assets to buy, or lavishly paying active fund managers to do the job for you, when every asset’s expected risk-adjusted return is the same?

All this assumes something rather important: that the risk-adjusted return (or the length of the queues) is indeed the same. Or at least that such returns look so similar to the trained eye that it is pointless to try to pick a winner. Another phrase to describe this idea is the “efficient markets hypothesis”. It is often viewed with suspicion because it sounds a bit Reaganite; in fact, it simply means you shouldn’t be too impressed by people who offer you stock tips.

We don’t know for sure that all financial assets have the same expected returns after appropriate adjustments for risk, partly because it is not clear what an appropriate adjustment for risk would be. It seems likely that they’re not far off.

One indicator of this is the performance of actively managed investment funds versus passive funds, which simply try to track some sector or market as a whole. Most active managers in most time periods do not manage to outperform passive funds – particularly not when their fees are deducted. As a matter of arithmetic, the average investor cannot beat the market because the market is the average of all the investors. But we might still expect that skilled active managers would consistently beat the average, and most of them cannot. Apparently skilled active managers often see their performance ebb over time, and for every Warren Buffett there are many one-hit wonders in the investment world.

What is more, active management is expensive. Even if you believe that an adviser could pick a faster-than-average supermarket queue to join, you might well be worse off pausing for a couple of minutes to take this advice, rather than choosing randomly without delay.

Active managers will have us believe otherwise, and occasional bunfights break out over whether actively managed funds are quite as bad as they seem but, for me, the logic in favour of passive investing is persuasive and the data even more so.

As this insight becomes better and better publicised, traditional fund managers are losing market share to low-cost exchange traded funds (ETFs) and, at the luxury end, to private equity groups. (The attraction of private equity is that you don’t shop in the supermarket at all. Whether the personal service at the delicatessen is actually worth what it costs is another question.)

I must confess, though, to a twinge of guilt – not a common emotion for the working economist. By passively investing or randomly choosing a supermarket queue, am I not taking advantage of the hard work of others? If everybody chose the first queue or investment that they came across, there would be no reason to expect a happy outcome. It is only because others are taking such pains to choose that I don’t have to bother.

This insight has become known as the Grossman-Stiglitz paradox, after Sanford Grossman and Nobel Memorial Prize winner Joseph Stiglitz, who back in 1980 published a paper pointing out that if financial markets were efficient, there was no benefit in paying for any sort of research or analysis; yet if nobody paid for any sort of research or analysis, why on earth would financial markets be efficient?

We passive investors like to congratulate ourselves on avoiding those parasites, the active fund managers, who charge high fees without delivering high returns. Yet we are parasites too, waiting for others to pay for research and then following the herd. Little fleas have lesser fleas, and so on, ad infinitum.

Passive investors shouldn’t feel too badly, though. This is a self-correcting problem. If most investors switched to passive funds, or picked supermarket queues at random, the market would be full of obvious errors and an active approach would pay off again.

I am beginning to make a study of supermarket queues already. It’s just a hobby – for now.

Also published at ft.com.