Tail event: Difference between revisions

{{L1}}'''Statistics''': Of a range of possible independent events, one whose frequency is three or more standard deviations from the mean. An event with a low probability <li>

'''Work life''': An unwanted outcome you didn’t expect and don’t think you should be blamed for.

We are, as the JC frequently complains, in swoon to the [[Reductionism|reducibility]] of all things. This usually involves converting all things that we do and that happen to us into numerical [[data]] points. Data points, in themselves, are no more  naturally [[effable]] than “things that happen to us”, of course, but numbers have the quality of submitting easily to aggregation and symbolic manipulation statistical techniques, in a way that “things that happen to us” do not.  

One can calculate an mean median and mode of a number, and one can subject standardised events to probability calculations. In the same way that I can calculate the probability of rolling consecutive sixes on a die (1/36), so we can calculate the probability of rain tomorrow, a tax cut in the spring, or a thirty point intraday drop in the NASDAQ.

Numbers are under control. They ''behave''. The bend to the spreadsheet ’s will.  

There is a great difference between a rolling die and a stock market. A rolling die is a “[[nomological machine]]”: a carefully constrained, sealed environment designed specifically to yield the theoretical outcome. The map is, as far as engineering permits, materially identical to the territory. We can, indeed, generate an indistinguishable outcome purely by running the model with a random number generator. The machined dice, the flat, constrained surface — these are a representation of the reality, which is the hypothetical model, and not the other way around.  A loaded die is a ''flawed'' machine. You don't chuck out the theory: you chuck out the equipment.

Likewise, if, inside your nomological machine there is a mischievous imp who catches and places the die as it sees fit, the conditions for your probabilistic calculation do not prevail. There is an interfering casual agent.  

Nomological machines are highly constrained, artificial, environments. If all their conditions are not satisfied, we can expect the world to behave differently without validating the machine. This is how, as Nancy Cartwright put it the laws of physics lie.

In any case these are the circumstances in which the rules of probability prevail.  Should the universe misbehave