This will come as a shock to the woman who thought that if she moved in with her boyfriend, he would see what a wonderful wife she’d make and ask her to marry him.

That’s one of the myths my wife and I identified in our book, Living Together: Myths, Risks & Answers. The man knows she would marry him if asked. By cohabiting he enjoys convenient sex, shared rent and companionship – without commitment.

When she discovers he is not serious, she moves out. However, she’s no longer the same hopeful, attractive young woman she was a year ago. Her searing experience has left her less self-confident, possibly embittered or depressed.

And she may well be pregnant or have a child. Cohabiting couples are nearly as apt to have a child as a married couple – 41% of those living together vs. 46% of married couples. Those children are three times as likely to be expelled from school or get pregnant as those from intact homes, five times more apt to be poor and 12 times more likely to be incarcerated.

“Uncle Sugar” to quote Mike Huckabee, has become involved. Unwed mothers are eligible for welfare, Medicaid, food stamps, the Earned Income Tax Credit, housing and day care subsidies, etc.

The Heritage Foundation estimated that in 2004 those subsidies cost taxpayers about $20,000 per unwed birth or divorce with a child. With inflation, that’s probably $25,000 today. With 1.61 million unwed births in 2011, the cost for one new year is a stunning $40.3 billion.

In a state like Texas, with 160,000 unwed births, taxpayers had to come up with a huge $4 billion for one year of births. What’s more, cohabiting couples who marry are more likely to divorce.

What can be done?

Texas will elect a new governor this year. If I were running, here’s what I would say. “If I am elected governor, and you have an out-of-wedlock child and are living with the father, Texas wants to encourage you to marry - the best answer for the child and for you parents. However, today’s law would cut off Medicaid, food stamps and benefits worth about $25,000 per year.

“Therefore, as governor I’ll propose a legal change so that if you marry, you would lose NO benefits for two years. Then your benefits would be tapered off over three years. Married men earn more than cohabiting men. They are more committed to their family, and need no subsidies. Texas would rather subsidize couples with children to marry than to subsidize cohabitation,” I’d say.

“In time, the costs to government will fall. I think we could save $1 billion to $2 billion a year as more couples marry and fewer children are born to unwed couples.”

Since 1990 the marriage rate in Texas has fallen by a third. Most of that decline has hit “Middle America,” the 60% of Americans aged 25 to 60 who have a high school diploma – but not a college degree. For them “marriage is rapidly slipping away,” according to “The State of Our Unions – Marriage in America 2012,” of the Institute for American Values.

“As recently as the 1980s, only 13% of the children of moderately educated mothers were born out-of-wedlock. By the late 2000s, that figure had risen to a whopping 44 percent.”

Bradford Wilcox wrote, “Marriage among the moderately educated middle begins to resemble the fragile state of marriage among the poor…of high school dropouts.”

By contrast, unwed births to the college-educated grew from only 2% to 6%.

The New York Times reported that more than half of all births (53%) to women under age 30 now occur outside of marriage. Most are to cohabiting couples.

Therefore what’s needed is what I call “Cohabitation Reform.” One aspect of that is to subsidize cohabiting couples to marry. Another is to deny benefits to cohabiting women who give birth. She has the benefit of her partner’s income as if she were married.

More will marry and children will have a better future.

Michael J. McManus is President of Marriage Savers and a syndicated columnist.