Once upon a time, during a brief egalitarian period in postwar America, people of different classes did not live in separate worlds. The promise of mobility and prosperity was alive throughout the land. In 1950, Walt Disney Productions was saved from bankruptcy with its smash hit "Cinderella," which audiences cheered at a time when the future looked bright and it was still possible for the dream of marrying up to come true.
A new Disney film of "Cinderella" is a big box-office success today, but how different things look! Cinderella marriages are getting to be as rare as golden coaches. Economist Jeremy Greenwood has found that your chances of marrying outside your income bracket have been dropping since the 1950s because of something called "assortative mating," which means that we are increasingly drawn to people in similar circumstances.
Since the 1980s, inequality has grown and mobility has stalled. Today, the rich forge their unions in exclusive social clubs, Ivy League colleges and gated communities. Unless you have a fortune or a fairy godmother, you're probably out of luck. Without that magic, the gates remain closed.