How much does such social regulation matter? History is our lab, and the results are clear. Every political community that has lasted long enough to leave a trace of itself has regulated male-female sexual relationships. Why? These alone produce new human beings — highly dependent little creatures who have the best chance of reaching physical, moral, and cultural maturity and of contributing to the community when reared by their own mothers and fathers in the context of marriage. But family stability doesn’t happen by chance. It requires a strong marriage culture: norms and subtle influences designed to guide people’s choices toward their own long-term interests and the common good.
Indeed, justice demands as much. By encouraging marital stability, the state vindicates a right — that of a child to know the committed love of his own mother and father for him and for each other. And it limits the impact of negative externalities on innocent parties, because failed marriages and out-of-wedlock births burden us all with a train of social pathologies and a greater demand for policing and state-provided social services. The research of sociologists David Popenoe and Alan Wolfe on Scandinavian countries shows that as marriage culture declines, the size and scope of state power and spending grow. Libertarians, please take note.