Hi, my SO is looking around for a PhD topic. I have an idea but I don't want to suggest it if it's been done to death or isn't actually a question that expands the field of knowledge.

Anyway, my idea is that she research whether economists are in the long run poorer, wealthier or the same depending on their specialization. I'm thinking she could break it down by macro, micro and also by adherents to various schools of economic thought.

So, has this topic been done? How can I phrase in economic jargon the kind of hypothesis that she'd be testing?

Hope you can help.

PS: I don't want to suggest it if the idea isn't solid - she gets quite prickly when we talk about her study (something about a certain engineer irritatingly explaining how pins are actually made and questioning why the people on the two islands don't just build a boat and go somewhere better).