Reading P3 and mt I got stuck at
…economics makes grandiose claims to be the science of collective behavior, or even the science of collective happiness. Yet it dismisses any philosophically interesting aspects of these questions in favor of counting dollar-denominated transactions. Nevertheless, it claims for itself a unique position among the sciences, as the crux, the central weighing mechanism, for all public decision-making.
Leaving to the side, if I can for the moment, the “philosophically interesting” aspects I’m interested in the “central weighing mechanism” point.
It isn’t clear to me if mt is rejecting (a) the idea of having a weighing mechanism, or (b) the idea that economics is it?
I don’t think (b) is plausible – economics is, pretty well by definition, the weighing mechanism. Assuming you believe in one.
That leaves (a) (I think. Are there other options?). I think that’s a bad choice – the only alternative to a central mechanism is a decentralised mechanism, where everyone uses their own prejudices. Which is the bad bits of the current political mess (if you want an example of decision-making not based on economics, then try this or more generally). I think you want more economics, not less, but done properly.
Once upon a time I think I would have rejected (a), or perhaps I would have not got past my reservations over it. There are still immense problems with reducing everything to a common monetary unit (e.g. Stern is broken). But I now think that to refuse to accept (a) is just to stick your head under a blanket. These decisions and trade-offs will be made anyway; its impossible not to make them. So they should be made in the best way.
[Update: if you want an example of why doing things non-economically is a bad idea, try this].
* Carlyle and the Racist Origins of the Idea that Economics was “the Dismal Science”
* The crash wasn’t derivatives and it wasn’t big banks: as Spain shows
* Covered in Bees finds mt a bit hand-wavy too.