>Okay, it probably isn't fair to blame Billy Crystal and Meg Ryan for our widening income gap. But it is fair to say that When Harry Met Sally tells us something about why the rich have been getting so much richer than everyone else. That's high-earning college grads marrying each other—which a new paper estimates has increased inequality by 25 percent.

First take after quick reading that it is a statistical fluke due to incomparable sampling, probably just from having more people (females to an even higher degree) entering the better scaled shake-out process of education. YOu had marriage customs inside the same strata for ages and nobility has its own rules on inheriting things to keep fortune/wealth together.