The author goes on to suggest that the signalling value of a college education is actually declining as well - something which tracks with a notion that I've been noodling with that online higher-education (really online certification) will start breaking down the existing higher-education structure very soon.
My hypothesis is that it is precisely the dumbing down of U.S. education over the last decades that explains the increase in willingness to pay for education. The mechanism is diminishing marginal returns to education. Typical graduate business school education has indeed become less rigorous over time, as has typical college education. But typical high school education has declined in quality just as much. As a result, the human capital difference between a college and high-school graduate has increased, because the first increments of education are more valuable on the job market than the later ones. It used to be that everybody could read and understand something like Orwell’s Animal Farm, but the typical college graduates could also understand Milton or Spencer. Now, nobody grasps Milton but only the college grads can process Animal Farm, and for employers the See Spot Run–>Animal Farm jump is more valuable than the Animal Farm–>Milton jump.
Once that happens - and I think it will happen - I tend to think that such a seismic shift might make it easier to add rigor back to the lower forms of schooling. Am I hopelessly optimistic?