A few days ago Bryan Caplan wondered why economists question whether bringing someone into existence makes them better off, and I had some objections. Bryan has offered up a useful response, in which I think he has inadvertently answered his own question.

He responds to two of my challenges, in which I broadly claimed that if he were right, it would be a moral imperative which would trump all others to bring as many people into existence as possible, which seemed to violate common sense morality. He agrees that this is a bullet to bite for strict utilitarians, but adherents to other moral positions can rationalize not having to behave with an observation that begins “People who actually exist count a lot more than people who could exist but don’t.” This, however, answers the question he asked in the first place, which was:

If someone gives another person the gift of life, however, I’ve noticed that many economists suddenly become agnostic.  $100?  Definitely an improvement.  Being alive?  Meh.

It’s hard to see the logic.  Why would a minor gift of cash be a clear-cut gain, but a massive gift of human capital be a question mark?

Understanding that the cash gift makes someone better off requires nothing more than strict utilitarianism, the mode of analysis economists are trained in. The gift of life however requires something more than strict utilitarianism, and requires some other moral position to justify it. Furthermore, it’s hard to think of a reasonable moral position according to which giving someone $100 does not make them better, whereas it is not so hard to imagine reasonable moral positions according to which the gift of life does not make someone better off. One is clear-cut and requires the usual tools of economic analysis, the other is not and requires appealing to other moral positions.

Elsewhere, and speaking of bullet biting utilitarians, Robin Hanson outlines an economic analysis of which creatures should exist and which shouldn’t. But I think Robin has some big unspoken assumptions in his analysis. The general problem is we don’t know the preferences of the non-existent. Here is how Robin broadly describes how the analysis of which creatures should exist should be done:

Economically, creature X should exist if it wants to exist and it can pay for itself. That is, in a supply and demand world, if our only choice is whether X should exist, then an X that wants to exist should actually exist if its lifespan cost of resources used (including paying for any net externalities) is no more than the value it gives by working for others.

The problem is that we don’t know the preferences of the non-existent, and so we don’t know Robin’s first requirement: whether creature X wants to exist.  Not only that, but according to Robin’s efficiency criteria you have to know whether they prefer an existence conditional on that existence includes paying their costs, and not just existing as a freeloader. You could argue that we could poll the existing and see if they would have preferred to never exist, but we don’t know whether the preferences of the non-existent have any relationship at all to the existing.  In addition, for many creatures we have no way to do even this post-existence polling. How do you understand a dogs preferences for existing versus never existing? And remember, showing a preference for continuing to exist over ceasing to existing is not the same as preferring to existing over never existing.

The problem with both of their analysis is the preferences for existing versus never existing are facts simply knowable through economic analysis, and must be brought from somewhere else. That is why, contra Bryan, I don’t think the value of the gift of life is not clear-cut to economists as the value of a $100 gift, and contra Robin, I don’t think knowing which creatures should exist is amenable to cost-benefit analysis.

I should add that, probabilistically, by simultaneously disagreeing with Robin Hanson and Bryan Caplan, I recognize I am likely wrong. So if I were to bet on these propositions, I would bet against them.