The Green Lumber Problem, outlined in Nassim Taleb’s upcoming book Antifragile, is essentially misunderstanding which facts are relevant vs those which are not in regards decision making under uncertainty.

From Nassim:


“In one of the rare noncharlatanic books in finance, descriptively called What I Learned Losing A Million Dollars, the protagonist makes a big discovery. He remarks that a fellow called Joe Siegel, the most active trader in a commodity called “green lumber” actually thought that it was lumber painted green (rather than freshly cut lumber, called green because it had not been dried). And he made a living, even a fortune trading the stuff! Meanwhile the narrator was into theories of what caused the price of commodities to move and went bust.

The fact is that predicting the orderflow in lumber and the price dynamics narrative had little to do with these details —not the same ting. Floor traders are selected in the most nonnarrative manner, just by evolution in the sense that nice arguments don’t make much difference.”

Here is a public discussion about the topic on his Facebook Page (Facebook account not required).

Nassim recently did a short opinion piece in the The New York Times Room for Debate area titled Throw Out the Probability Models (April 2012).

It covers his typical Black Swan message that we cannot predict these certain class of rare but consequential events and so we need to become robust to them rather then relying on forecasts. The economic models that we use to calculate the probability of these rare events needs to go out the window.

“What goes out of the window? The entire discipline of modern finance and portfolio theory (the theories named after Harry Markowitz, William Sharpe, Merton Miller), the model-based methods of Paul Samuelson, much of time series econometrics (which don’t appear to predict anything), along with papers and theories that are based on “optimization.” These bring fragility into the system.”

Click here to read full piece here together with a reader discussion taking place in the comments section.