Anyway, reading Jonathan Wolff on the cost of getting an undergraduate degree (thanks to Brian Leiter), this caught my eye:
Thomas Carlyle famously called economics "the dismal science". I saw this in action when on a panel, interviewing health economists. We decided to ask all candidates an amusing "unexpected" question at the end: "Which concept from economics should be better known by the general public?"
Any economist reading this will already know how they all answered: "opportunity cost". In judging whether it is right to spend money in a particular way, you should first think what else you could be doing with it. Could you squeeze out a little more value or enjoyment? Health economics is dominated by considerations of opportunity cost. When the government created a new fund for cancer treatments, for example, economists immediately asked what we would have to give up to pay for it.
Worrying about alternatives foregone is fair enough, but also pretty joyless. Imagine living your life under the shadow of opportunity cost. Any time you want to go to the cinema, you'd have to ask whether there is some other way of getting more out of your time and money. If there is, then you'll make a net loss, even if you'd really enjoy your evening out.It seems to me that Anscombe's views on numbers go completely against this. Her view, as I recall, is that we should do good and not bad (OK so far), and that as long as we are doing good we should not be criticized. This means that if I choose to save three orphans from a fire instead of fifteen orphans from a sinking ship then I have done nothing wrong. Wolff's economists would presumably say that the cost of my action was twelve orphan lives. This makes me sound like a murderer. (I'm assuming that the two actions were equally possible for me, and that neither was more risky than the other, and so on.)
Now, Anscombe's view is not obviously correct, but it is not irrational or obviously false either. This appears to be a case of the dismal science being dismal but not really a science in the sense to which it aspires. That is, it is not purely positive but in fact takes a debatable normative stance. But perhaps I've misunderstood, or failed to make clear the connection I see between what Wolff says and what Anscombe says.
About.com says that the opportunity cost is just what you would have done if you had not done what you did. So if I can choose to have my cake or eat it, but not both, and I eat it, then the cost is having it. This seems just like the case where I could save three or fifteen and choose to save the three. The cost is that I don't save the fifteen, so the fifteen die.
Anscombe might reject this partly because she rejects consequentialism. But there's also something funny, I think, about the idea that what I would have done instead could be a cost. Costs are real, not hypothetical. If I choose to have the cake instead of eating it, I don't lose the eating of the cake. I just don't eat it. Similarly, if I gamble $100 on a horse race and lose, then I have lost $100. But if I simply don't go to collect a $100-bill from someone who is giving them away then I lose nothing. I am worse off than I would have been otherwise but not worse off than I was. What I would or could have done is not some thing that I can lose. The idea of opportunity costs, in short, seems to me to be metaphysically confused, as well as dubious morally.
Maybe my economist friend will explain to me why I'm wrong.