Robo economicus

A common criticism of economists is that their theories work if people behave like perfectly rational preference-maximisers but not if they behave like people. My understanding is that this criticism is a load of baloney, because economists are well aware that people don’t always behave as homo economicus would, it’s still a useful idealisation with genuine predictive and explanatory power, and economists study how much and in what ways the idealisation differs from the reality. Perhaps I’m wrong about this. I doubt it though, because if the criticism was justified then the rational thing would be to write a paper pointing it out and scoop the Nobel prize, and nobody’s done that.

This said, economists do seem to be better at explaining things than they are at predicting them, and maybe if people behaved more like the idealisations then economic behaviour would be easier to predict. My suggestion is that we make a lot of artificially intelligent robots that really do behave like that, give them a bunch of money and release them into society.

Part of the beauty of this is that economies would become more predictable. The other part is that we could programme the robots to have the preferences we have but aren’t rational enough to maximise even when we have the means to do so. If we want more hospitals built, we could entrust their construction to corruptible, fallible humans, or to incorruptible, infallible, single-minded robots. The hospitals would be built as efficiently as possible, and as an added bonus the robot would be delighted.

I’ve long wondered why the government can’t stimulate the economy by pumping a load of money into international development, so the world gets developed by the invisible hands of the profit motive instead of by the sporadic largesse of the notoriously self-obsessed, myopic and capricious general public. I’m sure there’s a reason we can’t do this, or we’d have done it. But even if governments can’t create a market for that sort of thing, I don’t see why a rampaging rabble of rich rational robots couldn’t. It that pays the piper calls the tune.

The problem of transobject identity

Yesterday I finished reading the first volume of David Armstrong’s Universals and Scientific Realism for the first time. It’s fun, interesting and short. I recommend it, even though some of the arguments probably aren’t the kind of thing you can get away with nowadays. Armstrong is dealing with the problem of how different things can be the same in some respect, and he argues that nominalism, Platonism and trope-theory either don’t explain what needs explaining or lead to explanatory regresses. Since these are bad things, he adopts a theory of immanent universals, which are repeatable things which crop up in different objects. If two particulars are both negatively charged, that’s because there’s a thing, negative charge, which is in both of them. I wouldn’t say I was convinced, but he makes the case pretty well.

Now, when I was reading it, I noticed a parallel between the problem Armstrong is addressing and the problem of transworld identity. Armstrong wants to know how different things can share properties, and the problem of transworld identity is about how different possible worlds can share inhabitants. Some issues in one debate have corresponding issues in the other, and this gives rise to analogies between the positions. I think at one point Armstrong even calls the thing he’s trying to explain ‘generic identity’.

Transworld identity gets explained by the worlds having either strictly identical things in them, or suitably similar things in them. Generic identity gets explained by particulars having strictly identical universals in them or suitably similar tropes. The ‘no explanation needed’ positions are magical modal realism, which reifies worlds but not possibilia, and ostrich nominalism, which reifies objects but not properties. (Both were named by their opponents.) Another parallel is that people disagree about whether particulars are bundles of properties or something besides their properties, and they also disagree about whether worlds are fusions of their inhabitants or something besides their inhabitants. The bundle theory of particulars is typically most plausible to trope theorists, and the fusion theory of worlds is typically most plausible to counterpart theorists.

When you spot a parallel between two debates it can help you in at least two ways. One is that the analogy can help us understand the more mysterious debate better. Our thinking about time became clearer when we realised it was a bit like space, and our thinking about modality became clearer when we realised it was a bit like time. I’m not sure whether we’ll be helped much in this way here: space and time really are quite like each other, whereas the relationship between a world and its inhabitants seems quite unlike the relationship between a thing and its properties, at least if the bundle theory isn't right.

The other way analogies between debates can help is more promising though. There’s some pressure to hold analogous positions in analogous areas, because a good argument for one position will often correspond to a good argument for the other. This way of killing a large number of birds with a small number of stones is particularly useful for people like me who like to make their minds up about things. For example, shortly after I came round to counterpart theory about de re modality I came round to stage theory about persistence. I’ve never really had a view about property ontology before, but maybe now I should have another look at trope theory.

How can this possibly be legal?

One of the measures which is standardly used to prevent corruption is making people in positions of power declare their interests. For example, if a politician is deciding which company gets a government contract, and the politician works for one of the companies in the running, they have to declare it and the decision may be delegated to someone else. If they don’t declare it and get found out, they get into trouble. It is fairly obvious that a system lacking this feature would be open to abuse.

One thing which seems to be allowed, however, is for a politician to take a job with a company after having used the power entrusted to them by the electorate to benefit said company. Private Eye reports on this sort of thing all the time. They call it the Revolving Door. I can’t see any principled reason to think that undeclared future interests compromise the integrity of the politicians involved much less than undeclared present interests would.

It seems to me that it would be pretty easy to put a stop to it. You say that politicians giving contracts to companies have to declare an interest or either face trouble or not take a job with the company for, say, five years. And if people keep waiting out the time limit and then immediately taking jobs with companies they’ve helped, we smell a rat and extend the time limit. But perhaps I’m missing something and a rule like this would be impossible to put into practice.