Thursday, June 3, 2010

On Knightian Uncertainty

An interesting post appeared recently attempting to distinguish between risk and uncertainty. The view was proposed by an economist called Frank Knight. The theory proposed by Knight is that risk is something where the outcome is unknown but whose odds can be estimated. But when the odds become inestimable, risk turns to uncertainty. In other words, risk can be measured and uncertainty cannot.

There are economists who argue that Knight's distinction only applies in theory. In the world of the casino, where the probability of a 21 turning up or the roulette ball landing on a certain number can be estimated, it is possible to have risk. But anything outside simple games of probability becomes uncertainty because it is difficult to measure the uncertainty. The real world out there is so complex that it is indeed difficult to make even reasonably short term projections, let alone the really long term ones. So what is really the truth here? Does risk (as defined by Knight) even exist in the world today? Or as the recent world events (be it 9/11, the Great Recession, the threatened collapse of Greece, the oil spill in the Gulf of Mexico, the unpronounceable Icelandic volcano) have revealed, it is a mirage to try and estimate the probability of something playing out with remotely close to the kinds of odds we initially estimate.

I have a couple of reactions. First, my view is that risk can be measured and outcomes predicted more or less accurately under some conditions in the real world. When forces are more or less in equilibrium, it is possible to have some semblance of predictability about political and economic events. And therefore an ability to measure the probability of outcomes happening. When forces disrupt that equilibrium and the disruptions may be caused by the most improbable and unexpected causes, then all bets are off. Everything we have learnt from the time when Knightian risk applied is no longer true and Knightian uncertainty takes over.

Second, this points to the need for the risk management philosophy (as it is applied to a business context) to not only consider what the system knows and can observe but also the risks that the system doesn't even know exist out there. That's where good management practices such as constantly reviewing positions, eliminating extreme concentrations (even if they appear to be value-creating concentrations), constantly questioning the cognitive thinking - can lead to a set of guardrails that a business can stay within. Now these guardrails may be frowned up and even may invite derision from those interested in growing the business during good times, as the nature of these guardrails are always going to be to try and avoid too much of a good thing. However, it is important for the practitioners of risk management to stay firm to their convictions and make sure the appropriate guardrails are implemented.

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