by Jo McGowan

About the author: Jo McGowan is a freelance writer.

For a person with a lot of friends, I've attended remarkably few weddings. Many of the people I know—white, middle-class, college-educated, liberal or left wing—have chosen to live together instead.

"Why spoil a good thing"" is how one woman puts it. But for most people it's just a way of hedging their bets. In a country where nearly half of all marriages end in divorce, people want to be absolutely sure before making that final commitment.

For those who still believe in the concept of marriage at all, living together is a kind of test run; and to the consumerist mind, which is what most of us have these days, it makes good sense. People don't buy a car without taking it out for...