Lentil convexity: Difference between revisions

{{A|g|[[file: Lentils.jpg|450px|center|thumb|Out of my cold dead hands.]]}}''Author’s note. I mean no slight on people who buy tinned lentils. I, personally, quite like them.''

 

So it turns out we haven’t been panic hoarding lentils after all. There is a benign explanation for the sudden disappearance of split peas from the nation’s grocery shelves.  

In ordinary times, our lentil-buying habits are regular: hippies and vegans (a small (but growing!) portion of the population) buy a lot of lentils, and everyone else buys none. Okay, ''almost'' none. The [[Reasonable man|person on the Clapham Omnibus]] might have ''one'' tin, at the back of the cupboard, that someone got in a weak moment years ago, just in case of unexpected apocalypse, or an unexpected visit from your long-lost, vegan, cousin from Australia.

But the peacetime lentil-buying motivations of a hippy, a vegetarian and the proverbial meat-and-potatoes munching, Clapham omnibus-riding ordinary fellow are quite distinct, and unrelated. Each person’s decisions are, within a fairly tight range, predictable and and independent of each other: ''my'' lentil acquisition does not greatly influence, and is not particularly correlated with, ''yours''.  

National weekly lentil purchases therefore usually cleave to a [[normal distribution]].  A small part of the population (say 0.5% - the hippies) may buy 8, 9 or 10 tins. A larger part (say 4.5% - vegans, health-food fanatics etc.) may buy one or two, and the remaining 95% will buy very few (lets’ say on average 0.1 tin each: one tin between ten, which is probasbly generous). The consequence of a normal distribution is standard deviations. The random variation in purchases by people in the different demographic groups will cause a small fluctuation in in demand for lentils from week to week, but from a grocer’ perspective, the demand curve is predictable and manageable.