Lentil convexity: Difference between revisions

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===Implications===
===Implications===
We can see the interconnectedness between human decisions like lentil-buying, at the extremes is not stable. You can’t model it. You can’t predict it. The [[correlation]] ''changes'' on account of the very ''existence'' of each buying decision, and each other people’s reaction to that decision. In ordinary times one person’s buying decision won’t affect another’s. They ''look'' for all the world like truly independent events. What do I care whether you bought lentils? But events which are ''really'' independent ''stay'' independent, however weird things get. The odds of flipping heads on a fair coin stays 0.5 however often you flip it, and whatever the previous results.<ref>Practical point though: the longer your sequence of heads, the greater the probability that the ''coin is not fair''.</ref> This makes the job of modelling independent events much, much easier. Your standard deviation stays put.  Modelling dependent events isn’t just a case of more complex maths. It isn’t ''possible''.
Events which are ''really'' independent ''stay'' independent, however weird things get. The odds of flipping heads on a fair coin stays 0.5 however often you flip it, and whatever the previous results.<ref>Practical point though: the longer your sequence of heads, the greater the probability that the ''coin is not fair''.</ref> This makes the job of modelling truly independent events much, much easier. Your [[standard deviation]] stays put.  


Mis-modelling overall lentil demand is a relatively low-stakes game. It is liable to annoy peaceniks — but they are dispositionally unlikely to foment insurrection — and (unless armageddon does arrive after all, in which case a lack of lentils is the least of our problems) actual bodily consumption of lentils won’t change, so the supply-shortage will quickly sort itself out, as the 95% find themselves unexpectedly long more lentils than they know what to do with and their part of the demand curve hits absolute rock bottom.
Interconnected events don’t. They go from stable, most of the time, to flat-out nutso in extreme times. Fair coins don’t go nutso. Dice don’t go nutso. Lentil buying ''can'' go nutso. You can’t model it. You can’t predict it. The [[correlation]] between events then changes further ''because it’s gone nutso''. There’s a feedback loop.  


But it is a nice illustration of how badly a normal curve can serve you when the chips are down.
The point? Modelling normal distributions of independent events is easy, and safe. Modelling distributions of interconnected events isn’t. It isn’t just a case of more complex maths. It isn’t ''possible''. Now, mis-modelling overall lentil demand is a relatively low-stakes game: liable to annoy peaceniks — who are dispositionally unlikely to foment insurrection, and it’s kind of amusing anyway — plus, realistically (unless it ''is'' Armageddon, in which case a lentil shortage is no longer the problem) actual consumption of lentils won’t change, so the supply-shortage will quickly sort itself out, as the 95% find themselves long more lentils than they know what to do with and their part of the demand curve hits absolute rock bottom. So a spot of convcexity might not matter for the worlds’ lentil purveyors, but how about the global transport and hospitality industries? I mean, what would ''they'' do if everyone around the world, without warning, as one, stopped leaving their houses indefinitely?
 
Like ''that'' would ever happen.


{{sa}}
{{sa}}

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