In social psychology, there is a classic theory called “exchange theory.” It is a bit cold-blooded, but it predicts that a person’s actions will be based on trying to find a balance of give and get. Each person’s resources — of all kinds, including money, looks, background — are traded back and forth for a “good deal.” For example, a “good deal” scenario could be a woman who makes an excellent living pairing up with a man who is a writer and is willing to work at home and be the primary child care person.

When women’s life choices were highly constrained, they had little negotiating power. They had to marry or were seen as damaged. A few got away with being “free spirits” but usually they were exceptional in wealth or lineage — and even so, it wasn’t easy.

It’s different now. While most women still want marriage, they don’t want it at just any price. They don’t want it if it scuttles their dreams. Marriage is not dead — not by a long shot. It is still, to most of us, the house we wish to build for our love, our lover and our children.