My first post here - please be kind!
I've recently been listening to and reading various arguments around EA topics that rely heavily on reasoning about a loosely defined notion of "expected value". Coming from a mathematics background, and having no grounding at all in utilitarianism, this has left me wondering why expected value is used as the default decision rule in evaluating (speculative, future) effects of EA actions even when the probabilities involved are small (and uncertain).
I have seen a few people here refer to Pascal's mugging, and I agree with that critique of EV. But it doesn't seem to me you need to go anywhere near that far before things break down. Naively (?), I'd say that if you invest your resources in an action with a 1 in a million chance of saving a billion lives, and a 999,999 in a million chance of having no effect, then (the overwhelming majority of the time) you haven't done anything at all. It only works if you can do the action many many times, and get an independent roll of your million-sided dice each time. To take an uncontroversial example, if the lottery was super-generous and paid out £100 trillion, but I had to work for 40 years to get one ticket, the EV of doing that might be, say, £10 million. But I still wouldn't win. So I'd actually get nothing if I devoted my life to that. Right...?
I'm hoping the community here might be able to point me to something I could read, or just tell me why this isn't a problem, and why I should be motivated by things with low probabilities of ever happening but high expected values.
If anyone feels like humoring me further, I also have some more basic/fundamental doubts which I expect are just things I don't know about utilitarianism, but which often seem to be taken for granted. At the risk of looking very stupid, here are those:
- Why does anyone think human happiness/wellbeing/flourishing/worth-living-ness is a numerical quantity? Based on subjective introspection about my own "utility" I can identify some different states I might be in, and a partial order of preference (I prefer to feel contented than to be in pain but I can't rank all my possible states), but the idea that I could be, say 50% happier seems to have no meaning at all.
- If we grant the first thing - that we have numerical values associated with our wellbeing - why does anyone expect there to be a single summary statistic (like a sum total, or an average) that can be used to combine everyone's individual values to decide which of two possible worlds is better? There seems to be debate about whether "total utilitarianism" is right, or whether some other measure is better. But why should there be such a measure at all?
- In practice, even if there is such a statistic, how does one use it? It's hard to deny the obviousness of "two lives saved is better than one", but as soon as you move to trying to compare unlike things it immediately feels much harder and non-obvious. How am I supposed to use "expected value" to actually compare, in the real world, certainly saving 3 lives with a 40% change of hugely improving the educational level of ten children (assuming these are the end outcomes - I'm not talking about whether educating the kids saves more lives later or something)? And then people want to talk about and compare values for whole future worlds many years hence - wow.
I have a few more I'm less certain about, but I'll stop for now and see how this lands. Cheers for reading the above. I'll be very grateful for explanations of why I'm talking nonsense, if you have the time and inclination!