Well, maybe at the University of Chicago, that is what is taught, but is it true?
It may be inevitable under our current structures, but if one gets outside that box, and looks deeper, one finds other answers.
I would suggest that Mr. Kaplan, who teaches economics at the Graduate School of Business at the U of C, look beyond the interests of the university's and b-school's founders and big donors and alumni and current students, and consider that we're all in this together, and that when we permit a few to monopolize and privatize things which rightly are our common treasure, inequality is the inevitable byproduct.
Mr. Kaplan might start by exploring the ideas of Henry George. They were in his freshman economics texts, but most likely his instructor didn't lecture on them, or include them in exams (most likely because his own instructors hadn't!)
Read what those textbooks have to say, and then think about whether it is in Mr. Kaplan's personal career interests to speak of an idea that could rock the yachts of alumni and donors and others who like our current structures just fine, thank you! The privileged like their privileges, and would prefer that we not notice that they are privileges, or, if we do notice, think that THEIR privileges are somehow in OUR best interests.
An impolite fiction!