Uncertainty and Irrationality

Clear and coherent markets, free from political agenda, bad compromises, and ineffective regulation is almost nonexistent. The consequences are usually pyrotechnic. It is not as if the world hadn’t provided ample warnings about the risks associated with irresponsible finance. History has centuries worth of such examples, but even looking at recent events over the last 25 years is illuminating.

In spite of Alan Greenspan acknowledging the “irrational exuberance” of the markets in 1996, stock market valuations continued to rise. The warning signs of unstable economies were believed to be localized and the broader markets decoupled from this turbulence. This was na├»ve thinking then and outright irresponsible now.

The idea that markets are uncertain, and consistent prediction is essentially impossible, is not new. John Maynard Keynes published a book on probability and uncertainty in 1921, with this concept of uncertain and irrational markets forming the basis of his general theory of financial markets. So, years before the stock market crash of 1929, and almost every 10 to 15 years afterward, the cycle of financial crashes and panics was predicted by a well-publicized thinker, and then, as is typical, ignored. The lesson is simple, and Keynes laid it out 100 years ago: markets seem rational but only during periods of stability. Markets are uncertain. Predictive models work most of the time, and that is their fundamental flaw. They will fail. Investment models that account for uncertainty and failure succeed in the long term.