If you want to be a dentist, it's rational to assume that if you go to school, get your degree, and set up a dental practice, you will be able to attain a comfortable standard of living. You may be able to project your probable income range with some degree of accuracy.
But if you want to be a rock star, it's irrational to assume that if you go to rock school, get good at guitar, and start a band, you will become rich and famous.
According to Nassim Nicholas Taleb's way of thinking, the dentist and the wannabe rock star fall into two distinct categories with drastically different risk characteristics. The dentist falls into the domain he calls 'Mediocristan', and the rock star, 'Extremistan'. Extremistan is dominated by 'fat tails', or rare but profoundly significant events. Problems arise when we think we're operating in Mediocristan but in fact are operating in Extremistan."Karl Marx wanted to turn knowledge into action, what I want to do is turn our lack of knowledge into action". Taleb suggests that by becoming aware of our own ignorance, we can stop taking action where our action is irrational.
I'm on my second reading of Fooled By Randomness and am very much looking forward to The Black Swan. In the meantime I've been hunting down all the audio I can find on Taleb because his talks are extremely interesting and he is a very engaging speaker. He has a bit of attitude when addressing an audience, in part no doubt because much of what he has to say offends of lot of people, especially anyone whose expertise is related to forecasting. He has obvious disdain for financial forecasters in particular, probably because he sees the impact these 'guys in suits riding around in limousines' have on the lives of 'people taking the subway to work everyday' (i.e.pensions).
What Taleb has to say has resonated with me at a very deep level. Much of the facts and studies he brings to light confirm my long lingering suspicion that something about the way the world sees itself is profoundly inaccurate and weirdly irrational.
I've listened to each of these talks at least a half dozen times and every time I do I take away another profound insight. Be sure to check out Taleb's Home Page as well.
Taleb on EconTalk.org April 30, 2007
LongNow Lecture-The Future Has Always Been Crazier Than We Thought Feb. 4, 2007
And from PopTech 2005:
Nassim Nicholas Taleb is not afraid to say "I don't know." In fact, he's proud of his ignorance. A mathematician, philosopher and hedge-fund manager all in one iconoclastic package, Taleb demonstrates the wisdom in admitting the limitations of our knowledge.
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