[fighterpilot]

> 'Preppers', by definition, are those who have decided the world is unstable and on the brink of collapse.

Not by definition. Maybe in practice.

You might be a 'prepper' even if you think the chance of society collapsing is only 0.1% because you think it's a prudent hedge against a highly unlikely worst-case scenario. This might be rational from a personal perspective if you have enough wealth to burn such that 'prepping' for this 0.1% situation only costs 0.01% of your net worth.

[ericbarrett]

I have known some preppers and I think there's a pretty clear line when it crosses into a paranoia, and begins consuming your life. A rich person building a panic room or even a very rich person buying an island is a different from somebody of humble means who eschews working, to live in the boondocks and stockpile ammo and food. But I don't think money itself is the divisor; a modestly wealthy person buying an island to escape Armageddon might also qualify.

[mulvya]

Oxford defines prudent as "sensible and careful when you make judgements and decisions; avoiding unnecessary risks"

How can it be sensible if one thinks it's 'highly unlikely'?

If one is very rich, then prepping may be financially affordable, but that doesn't make it cognitively rational.

[fighterpilot]

> How can it be sensible if one thinks it's 'highly unlikely'?

Hedging a highly unlikely situation can still be sensible. Those two things are definitely not mutually exclusive.

If all your net worth is tied up in your house, it's probably sensible and rational to get fire insurance on your house, even if it's highly unlikely that your house will burn down. This question has been studied extensively in utility theory.

[goatlover]

But should you get insurance in case a meteor hits your house? Fires happen often enough, but some events are low enough probability not to worry about. A house being destroyed by a meteor strike isn't worth spending money on.

[fighterpilot]

X = P(bad_outcome) * magnitude_of_badness

Y = your net worth

You can trade-off one with the other.

People with lots of Y will be more happy to reduce Y in order to reduce X, because the marginal utility of Y declines with larger values of Y, whereas marginal utility of X remains roughly the same irrespective of values of Y.

> Fires happen often enough, but some events are low enough probability not to worry about.

This ignores the second part of X, which is magnitude_of_badness. Your house burning down has a smaller magnitude_of_badness than society collapsing which will likely lead to death.

It's also ignoring the marginal utility of wealth for large values of Y. Even if X is small, people with large Y will be more happy to reduce Y in order to reduce X.