Everybody look at your pants

[cincinnatus_c]

Here's a feature of practical reasoning that I think about a lot, which is somewhere in the neighbourhood of the lottery paradox but has nothing in particular to do with it (though every time I think about it much I have to go look at that lottery paradox article again): suppose, say, there's an activity, like riding in the back of a pick-up truck, that will kill, say, over the course of an average century, one out of a hundred thousand people--or, to turn the emotional screw, children--who engage in it. Supposing this, in a town of a thousand people, most likely no one will die engaging in it in anyone's lifetime, while in a city of three million people a bunch of people will. If you live in the city you will periodically hear about people in your city being killed by it, while in the town you will never hear about people in your town being killed by it. Given this, in the city, you might tend to perceive that this is a very dangerous activity; in the town, you might tend to perceive that it is completely safe.

I think where this comes up, practically, most often (apart from things much like riding in the backs of pick-up trucks), is rural vs. urban expectations of being victimized by crime. In the country you leave your doors unlocked because nobody around you ever gets burgled. But no one around you ever gets burgled because, relative to the city, there's hardly anyone around you. (But if you read the crime reports in the regional papers, you see that people in the wider region you live in, as opposed to your neighbourhood or town, get burgled a lot.)

I also think of a conversation I once had with an older person about canning--I said something about home canning of certain vegetables, like tomatoes or something, being unsafe; she was surprised and said she'd never had any problem with it. If you're getting your information on canning from your mother (etc.) and/or your own experience, certain things will appear safe to you because the odds of something going (catastrophically) wrong are such that nothing is likely to ever go wrong for you or even for your whole family. But if you're getting your information from someone on the internet, they might have to tell you that those things are unsafe and advise you not to do them, because their audience is big enough that something will go catastrophically wrong for at least one person and possibly many people who try them (even following directions perfectly).

Put in lottery terms: suppose there's a standard 6/49 lottery, such that any ticket's odds of winning are one in nearly 14 million, and it sells a hundred tickets a week. This lottery would produce a winner, on average, once every nearly 2700 years. Obviously no one except the most magical of thinkers would play such a lottery; no one would win in most people's lifetimes. But the odds of winning would be exactly the same as they are for the 6/49 lotteries we actually have.

So, given this, you could say that the bigger your community (the definition of "community" here has to be specified in some way I'm not sure of offhand) is, the more things will seem unsafe to you. And if you are determined to prevent "just one x", how much you have to do to prevent just one x will depend on how many people under the potential influence of your preventative measures are susceptible to x. In the city, you have to ban riding in the back of pick-up trucks; in the town, maybe not--except that once the isolation of the town as a community breaks down, maybe you do, too, because now you have to be part of the wider effort to prevent "just one x" across that wider community.

--
Currently at Belmont Lake: 5.2. High there today: 7.4. Currently under my porch: 4.2.

Comments

[meanwright]

I see two things here:

(1) The lottery _remains_ a bad idea, despite the fact that, with enough people, you now have the ability to advertise the bad idea so that it seems good.

(2) Canning* may _become_ a bad idea, although I'd expect that it becomes, on average, a bad idea because of technology - for food storage in general, not just canning. But that technology requires a large number of people.

The value of canning as a personal activity changes as you increase the population size, not so with the lottery - or with the pickup trucks.

The question I'd have, here, is how does the perceived value or risk changing line up with the availability heuristic: do you see something more to it, or not?

I should say that I think leaving doors unlocked where I am, right now, is perfectly fine - despite Y's misgivings. My Aunt M didn't lock her doors in a similar place in DC and doesn't in a more rural one in PA.*3 This was not true for NOLA, where I'd hear people trying my door every couple of months. So, I always locked my door.*4 I think people's subjective assessments are actually pretty good, before they are terrorized by headlines.

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* I remember that the USDA had a list of these kinds of "Don't Believe Your Grandmother" kinds of things. Some of them may be true in general - you risk e coli poisoning if you marinade your steak overnight. But they may have to do with changing standards - despite eating and drinking the same things, I tend to get e coli poisoning** when traveling while Y., coming from somewhere with lower food standards than the US, does not.

** Montezuma's Revenge, Deli Belly, etc. Now, to be culturally sensitive, traveler's diarrhea - blaming the victim is better than offending other people.

*3 But, paraphrasing John Le Carre, no thief in history's idea of the ideal haul is a shitload of books.

*4 And, if I forgot to lock my car door, it would smell like cigarettes when I started it up in the morning.