Wei Dai comments on A fungibility theorem

[Wei Dai]

It’s likely that someone has previously used the hyperplane separation theorem to justify being an optimizer, but I don’t know of any source that does that.

Will_Sawin said:

I think the fact that Pareto is equivalent to utility-weighting is well-known in economics. It’s one of the consequences of the separating hyperplane theorem.

ETA: Maybe he was referring to second fundamental theorem of welfare economics?

[Nisan]

Thanks! Added to the post.