For years, the slogan "Stay in School" has communicated an anti-poverty message to young people. Now it's time for an even more important poverty-fighting theme: "Get Married." Every student knows that dropping out of high school will hurt her chances of succeeding in life. Major media, public education campaigns and government programs have told her so.

But does she know that having a baby outside marriage will put her and her child at serious risk of living in poverty? Last year, poverty in America grew more than ever before in the 51 years that the U.S. government has tracked the poor, the Census Bureau reported Sept. 16. The total climbed by 3 million to 44 million — or one in seven Americans.

The search is on for solutions. Regrettably, too little of the conversation is turning to the principal cause of child poverty: the collapse of marriage.

Waiting until marriage to have children is the second of three "golden rules" for avoiding poverty that researchers identified over the years: (1) graduate from high school; (2) marry before having children; and (3) get a job.

Actually, being married is even more significant than graduating from high school for avoiding poverty. Robert Rector, a senior research fellow at The Heritage Foundation, shows this in a new paper, "Marriage: America's No. 1 Weapon Against Child Poverty." By contrast, typical responses to poverty call for more spending on government programs. Far from helping poor Americans escape dependency, however, massive increases in welfare spending over the past four decades have entrenched poverty across generations.

Proponents of a government solution also cite lack of quality education and decent-paying jobs. True, inner-city schools often are appallingly sub-par, but ever-increasing spending hasn't significantly improved educational quality and opportunity for those who need it most.

And although the bad news on poverty in part reflects increased joblessness during the recession, the economy doesn't explain the undercurrents trapping millions in persistent poverty. Three of every four Americans defined as poor — 35 million of the 44 million total — are poor during economic booms, Rector notes.

Government anti-poverty programs fail because such persistent poverty is not primarily material. It's about relationships and behavior. Even in good times, fatherlessness and lack of work trap the underclass.

Unwed childbearing has risen from 6.3 percent of all births in 1964, when President Lyndon Johnson launched the War on Poverty, to more than 40 percent today. As Rector shows, these single-parent families with children are six times more likely to be poor than are married couples with kids. Put differently, marriage lowers the probability of child poverty by 82 percent.

So why have we ignored the obvious? After all, marriage has been the standard in every human society.

"Marriage is the way societies provide a map of life and norms about behavior," researcher Kay Hymowitz says.

Role models and explicit messages create norms in society. That's why it's troubling to see the emergence of a "pattern of family non-formation," as scholar Heather MacDonald describes it.

Hymowitz and MacDonald, both affiliated with the Manhattan Institute, were among leaders invited by the U.S. Commission on Civil Rights to participate in a conference recently in Washington, by addressing the topic of "The Role of Family Structure in Perpetuating Racial and Ethnic Disparities." In minority communities, the collapse of marriage has become especially acute. More than half of Hispanic children are born to single mothers, as are seven out of 10 black children.

Among Hispanics, families headed by unmarried parents are three times more likely to be poor. For blacks, these families are five times more likely to be poor.

Meanwhile, the growing trend is "multi-partner fertility"—an antiseptic term to describe the relational mess of women having children by more than one man.

The Commission on Civil Rights deserves credit for tackling a subject too long considered off-limits. With lives at stake, America cannot afford to ignore these plain facts any longer.

How can we restore a cultural consensus on marriage and reduce child poverty? Rector suggests seven ideas. Among them: Policymakers should reduce anti-marriage penalties in welfare programs. Welfare offices and federally funded birth control clinics should provide facts about the value of marriage in fighting poverty.

And, in low-income neighborhoods and schools with a high proportion of at-risk youth, public education campaigns should teach the benefits of marriage.

If we're asking fathers not to walk away from their children, Americans must not walk away from the difficult task of restoring a culture of marriage.