Mauboussin on the Santa Fe Institute and Complex Adaptive Systems

[indythinker85]

http://www.valuewalk.com/2013/11/mauboussin-santa-fe-institute-complex-adaptive-systems/

 

Elliot: Did you have a bias towards one market philosophy before you adopted the complex adaptive system mental model? 

 

Michael: Although I had a solid liberal arts background before starting on Wall Street, I had very little background in business or finance. As a result, I had few preconceived notions of how things worked. It’s a challenge to come up with clear conclusions based on an observation of what happens in markets. On the one hand, you see clear evidence that some people do better than the indexes and that there are patterns of booms and crashes over the centuries. These suggest that markets are inefficient. On the other hand, there’s also clear evidence that it’s really hard to beat the market over time, and that the market is more prescient than the average investor. So for me, at least, there was an intellectual tug of war going on in my head.

 

I have to admit to being struck by the beauty of the efficient markets hypothesis as described by the economists at the University of Chicago. At the forefront of this, of course, was Eugene Fama, who recently won the Nobel Prize in part for his work in this area. What’s alluring about this approach is that it comes with a lot of mental models. You can equate risk with volatility. You can build portfolios that are optimal relative to your preference for risk. And so forth. Because you can assume that prices are an unbiased estimate of value, you can do a lot with it. The market’s amazing ability to impound information into prices impresses me to this day.

 

So it was with this mental tug of war as a backdrop that I learned about the idea of complex adaptive systems. Suddenly, it all clicked into place. A simple description of a complex adaptive system has three parts. First, there are heterogeneous agents. These can be ants in an ant colony, neurons in your brain, or investors in a market. Second, these agents interact leading to a process called “emergence.” The product of emergence is a global system that has properties and characteristics that can’t be divined solely by looking at the underlying agents. Reductionism doesn’t work.

 

What instantly drew me to this way of thinking is that it describes markets very well and it is very common in nature. The central beauty of this approach is that it provides some sense of when markets are likely to be efficient—in the classic sense—and when inefficiencies will creep in. Specifically, markets tend to be efficient when the agents operate in a truly heterogeneous fashion and the aggregation mechanism is working smoothly. Diversity is essential, both in nature and in markets, and the system has to be able to take advantage of that diversity. There are some neat examples in experimental economics to show how this works. It’s really wondrous.

 

On the flip side, when you lose diversity the system can become very inefficient. And that’s also what we see in markets—diversity loss leads to booms and crashes. Now the loss in diversity can be sociological, in which we all start to believe the same thing, or it can be technical, such as the winding up or winding down of a leverage cycle. But here we have a framework that accommodates the fact that markets are pretty darned good with the fact that they periodically go haywire. And SFI was at the center of this kind of thinking.