The Success Equation, Untangling Skill and Luck

We like to read around here – and just recently got done with one that has been on the wish list (it’s more like a… when the kids are quiet for 10 minutes and there’s not a client dinner or conference in town or presentation for a business deal – as time permits list, but I digress) for quite some time: Michael Mauboussin’s, The Success Equation: Untangling Skill and Luck in Business, Sports, and Investing

The title caught our eye right away, being in the business of untangling luck and skill to a certain extent in helping clients identify and invest in alternative investment managers. The question at the end of the day is whether the impressive track record a client is considering investing in is the result of skill, or whether it is luck. If you’re a chess player – or even tennis, it’s nearly all skill. If you’re a hockey player… it’s way more luck than your agent would care to admit.

And what about an investment manager?  How much of that track record is skill versus luck. The manager themselves usually portrays it as skillful, and charges as if it were entirely skill – but even the most successful of managers have to admit there is some skill in there. How much, and what questions should you be asking to determine the role of skill and luck are the parts of Mauboussin’s book we’re most interested in.

Here’s his handy graphic breaking down the major sports, slot machines, roulette, and trading in the stock market on a pure luck to pure skill continuum.

Mauboussin tells us that where skill is the dominant factor, history is a useful teacher, but where luck is the dominant force, history is a poor teacher. And that the type of feedback you get is a good tool to measure how much luck there is in your endeavor. On skill side, there is a very close relationship between cause and effect; but feedback on the luck side is often misleading – where good decisions can lead to failure and poor decisions lead to success in the short run (due to luck).  For more on the latter – read anything by Nassim Taleb, who’s made a career pointing out that a lot of the skill you see in the world (the banker, insurance company, option trader, etc) is nothing more than the result of 1 out of a million people destined to be quite lucky.

Essentially – what worked in the past may not work in the future on a heavy luck endeavor (such as investments), which I guess the regulators knew long ago when they made it a requirement to put the ‘past performance is not necessarily indicative of future results’ disclaimer on investment documents.

To measure the effect of luck, he introduces us to the James Stein estimator and the ‘shrinkage factor’ (straight out of Seinfeld), shows us how reversion to the mean is highly dependent on how much luck is involved, and discusses how even when you know how much skill there is – you’re in trouble because skills deteriorate (he quotes a source as saying the peak age for matters of finance is 53, and after that our skills start to deteriorate).

We enjoyed two parts in particular:

One, the discussion of ‘the paradox of skill’, which he explains: as skill improves, performance becomes more consistent, and therefore luck becomes more important. Mathematically, if the variance in skill becomes smaller than the variance in luck – luck becomes the dominant factor. In his own words:

When everyone in business, sports, and investing copies the best practices of others, luck plays a greater role in how well they do.

He shows stats supporting this from baseball, where all of the hitters have gotten better, but the rough averages have remained the same. Why? Because the pitchers have gotten better too!  But the interesting part of this to us is in the investment realm, and more importantly – the alternative investment realm. The discussion sure gets you thinking about our modern world of global markets, derivatives, and mangers earning billions; and whether the world has become so skilled in analyzing and trading them – that any performance is due mainly to luck, and due for a healthy reversion to the mean?  It makes us think of all the money in systematic trend following, and whether there is a real world experiment in the ‘paradox of skill’ happening there before our very eyes. Are any variations in the performance of trend follower A versus Trend Follower Z due to luck? Are they outperforming due to luck in including Coffee in their list of markets – luck in risking 0.25% per trade and getting an extra Hog trade versus the guy who’s model was risking just 0.20%? And so on.  Are those differences skill, or luck?

Two, we also enjoyed Mauboussin’s discussion of the ‘dumb money effect’, which we know as emotional investing, or getting in at the highs, and out at the lows. He shows some stats calculating it costs investors 1% in returns each year, and that institutional investors  have foregone $170 Billion in value over a couple decades because of this dumb money effect.

Why do we do it?  We’re hardwired that way, with Mauboussin showing a survey where two-thirds of respondents admitted they tend to rely more on judgement when analysis becomes more complex, and how we tend to give disproportionate weight to whatever has happened most recently, buying when at all time highs and getting out when at lows, causing some specific losses:

Individual investors consistently earn results that are 50-75 percent those of market itself due to bad timing.

And if this dumb money effect is so prevalent among individual investors and institutional alike – should we really expect our managers to be immune from it? It’s not too hard to imagine an investment manager doing their own version of the dumb money effect – changing a model around after a streak of losses, adding more markets on a model which is doing well to expand its exposure, and so forth. This is the danger to perceived skill – where changes meant to help actually result in pushing the inevitable reversion to the mean back further.

You can’t help but feel a little hopeless upon finishing the book – and realizing just how much of investing (and life) is due to luck instead of skill. But the lesson to be learned shouldn’t be to pack it in and put your money under the mattress. The lesson for us is to realize luck’s part, to realize that impressive winning streaks are just that – streaks. That depressing losing streaks are just that – streaks. And that some luck (or lack thereof) means reversions to the mean, so avoid getting in at the tops and out at the bottoms.. avoid the dumb money effect. The lesson for us is that process matters a lot more than outcome in the short run, and that the more you base your investment decisions on the recent past, the more likely you are to be disappointed.