The Great Academic Migration

The academic food chain in its natural habitat! This is basically scientific natural selection at work. Mediocre mathematicians who can't handle pure abstraction find refuge in physics where they can hide behind experiments. Physics rejects then migrate to economics where they can make up models that nobody can falsify. And when those economists can't predict anything correctly? They simply retreat to economic history where they can just describe what happened without having to predict a single thing. It's the perfect academic survival strategy - each field is the witness protection program for the previous one!