...you would think they would somehow teach kids about this sort of principle before they let them have investment accounts let alone allocate years of training to wizard school.

Keltham will wait until they have ended up in a multi-agent-optimum; one of the many possible multi-agent-optima, which happens to have a lot of imaginary jellychips in the possession of Meritxell; such that, indeed, it is not possible to make all the students better off, by taking some of those away from her.

...you would think they would somehow teach kids about this sort of principle before they let them have investment accounts let alone allocate years of training to wizard school.

Keltham will wait until they have ended up in a multi-agent-optimum; one of the many possible multi-agent-optima, which happens to have a lot of imaginary jellychips in the possession of Meritxell; such that, indeed, it is not possible to make all the students including her better off, by taking some of those away from her and looking for a more evenly distributed optimum.