Tyler Cowen in Stubborn Attachments:
The real issue is that we don’t know whether our actions today will in fact give rise to a better future, even when it appears that they will. If you ponder these time travel conundrums enough, you’ll realize that the effects of our current actions are very hard to predict,
While I think we often have good ways to guess which action is more likely to produce better outcomes, I agree with Tyler than we face great uncertainty. Once our actions get mixed up with a big complex world, it becomes quite likely that, no matter what we choose, in fact things would have turned out better had we made a different choice.
But for actions that take on a moral flavor, most people are reluctant to admit this:
What probability do you assign to this conditional claim: the US would have been better off overall if the South had won the US civil war?
— Robin Hanson (@robinhanson) December 8, 2018
If you knew enough history you’d see >10% as the only reasonable answer, for most any big historical counterfactual. But giving that answer to the above risks making you seem pro-South or pro-slavery. So most people express far more confidence. In fact, more than half give the max possible confidence!
I initially asked a similar question on if the world would have been better off overall if Nazis had won WWII, and for the first day I got very similar answers to the above. But I made the above survey on the South for one day, while I gave two days for the Nazi survey. And in its second day my Nazi survey was retweeted ~100 times, apparently attracting many actual pro-Nazis:
What probability do you assign to this conditional claim: the world would have been better off overall if Nazis had won WWII?
— Robin Hanson (@robinhanson) December 8, 2018
Yes, in principle the survey could have attracted wise historians, but the text replies to my tweet don’t support that theory. My tweet survey also attracted many people who denounced me in rude and crude ways as personally racist and pro-Nazi for even asking this question. And suggested I be fired. Sigh.
Added 13Dec: Many call my question ambiguous. Let’s use x to denote how well the world turns out. There is x0, how well the world actually turned out, and x|A, how well the world have turned out given some counterfactual assumption A. Given this terminology, I’m asking for P(x>x0|A). You may feel sure you know x0, but you should not feel sure about x|A; for that you should have a probability distribution.
The more plausible scenarios seem to be 'accelerationist' ones.
I.e consider that Germany wins, take over much of Europe, and then gets overthrown by some anti-fascist European revolution which leads to all of Europe being some sort of relative utopia, free from the Cold War.
Or consider that the South wins, institutes some awful regime, and then the end of slavery comes from some anti-slaveholder cross-racial revolt, which institutes some near utopia in the U.S.
Thinking about this more there is an essential vagueness in the question. I could be asking something like: "If we could time travel and kill Hitler in way X that would save 1 billion utils but we'd have to reroll all subsequent years what's the chance that things would turn out better." This question just turns on the model we use for `rerolling' later years.
However, I think it's actually more common for people to understand the question as asking something like: how confident are you that (evaluated with respect to objective physical probability) that E(X| no nazis) > E(X| nazis) where X is sum of utils in years since 1940. This question doesn't depend at all on how variable the utils earned per year might be since that is averaged out in the expectation. It merely asks us to judge how confident we are in our assumption that on net the nazis were bad rather than say necessary to warn us off a much more destructive nuclear war that would have almost inevitably occurred otherwise.