# Counterfactual trade

_Counterfactual trade_ is a form of [acausal trade](http://wiki.lesswrong.com/wiki/Acausal_trade), between counterfactual agents. Compared to a lot of acausal trade this makes it more practical to engage in with limited computational and predictive powers. In Section 1 I’ll argue that some human behaviour is at least interpretable as counterfactual trade, and explain how it could give rise to phenomena such as different moral circles. In Section 2 I’ll engage in wild speculation about whether you could bootstrap something in the vicinity of moral realism from this.

Epistemic status: these are rough notes on an idea that seems kind of promising but that I haven’t thoroughly explored. I don’t think my comparative advantage is in exploring it further, but I do think some people here may have interesting things to say about it, which is why I’m quickly writing this up. I expect at least part of it has issues, and it may be that it’s handicapped by my lack of deep familiarity with the philosophical literature, but perhaps there’s something useful in here too. The whole thing is predicated on the idea of acausal trade basically working.

**0\. Set-up**  
Acausal trade is trade between two agents that are not causally connected. In order for this to work they have to be able to predict the other’s existence and how they might act. This seems really hard in general, which inhibits the amount of this trade that happens.

If we had easier ways to make these predictions we’d expect to see more acausal trade. In fact I think counterfactuals give us such a method.

Suppose agents A and B are in scenario X, and A can see a salient counterfactual scenario Y containing agents A’ and B’ (where A is very similar to A’ and B is very similar to B’). Suppose also that from the perspective of B’ in scenario Y, X is a salient counterfactual scenario. Then A and B’ can engage in acausal trade (so long as A cares about A’ and B’ cares about B). Let’s call such trade _counterfactual trade_.

Agents might engage in counterfactual trade either because they do care about the agents in the counterfactuals (at least seems plausible for some beliefs about a large multiverse), or because it’s instrumentally useful as a tractable decision rule which works as a better approximation to what they’d ideally like to do than similarly tractable versions.

**1\. Observed counterfactual trade**  
In fact, some moral principles could arise from counterfactual trade. The rule that you should treat others as you would like to be treated is essentially what you’d expect to get by trading with the counterfactual in which your positions are reversed. Note I’m not claiming that this is the reason people have this rule, but that it could be. I don’t know whether the distinction is important.

It could also explain the fact that people have lessening feelings of obligation to people in widening circles around them. The counterfactual in which your position is swapped with that of someone else in your community is more salient than the counterfactual in which your position is swapped with someone from a very different community -- and you expect it to be more salient to their counterpart in the counterfactual, too. This means that you have a higher degree of confidence in the trade occurring properly with people in close counterfactuals, hence more reason to help them for selfish reasons.

Social shifts can change the salience of different counterfactuals and hence change the degree of counterfactual trade we should expect. (There is something like a testable prediction in this direction, of the theory that humans engage in counterfactual trade! But I haven’t worked through the details enough to get to that test.)

**2\. Towards moral realism?**  
Now I will get even more speculative. As people engage in more counterfactual trade, their interests align more closely. If we are willing to engage with a very large set of counterfactual people, then our interests could converge to some kind of average of the interests of these people. This could provide a mechanism for convergent morality.

This would bear some similarities to moral contractualism with a veil of ignorance. There seem to be some differences, though. We’d expect to weigh the interests of others only to the extent to which they too engage (or counterfactually engage?) in counterfactual trade.

It also has some similarities to preference utilitarianism, but again with some distinctions: we would care less about satisfying the preferences of agents who cannot or would not engage in such trade (except insofar as our trade partners may care about the preferences of such agents). We would also care more about the preferences of agents who could have more power to affect the world. Note that this sense of “care less” is as-we-act. If we start out for example with a utilitarian position before engaging in counterfactual trade, then although we will end up putting less effort into helping those who will not trade than before, this will be compensated by the fact that our counterfactual trade partners will put more effort into that.

If this works, I’m not sure whether the result is something you’d want to call moral realism or not. It would be a morality that many agents would converge to, but it would be ‘real’ only in the sense that it was a weighted average of so many agents that individual agents could only shift it infinitessimally.