SEXUAL mores change faster than the law does. This has been the case with child marriage, which is generally defined as involving those under 18 but also includes girls (for almost all of them are girls) younger than 16. Depending on the law in different states, older men are allowed to marry minors if they get parental consent, a judge’s approval, or even just the nod of a clerk. Stories about the Republican candidate for the vacant Alabama senate seat, Roy Moore, and his pursuit of teenage girls when he was more than double their age have caused disgust, at least among those who believe the accusers. Legally, though, Mr Moore could almost certainly have married even his 14-year-old accuser had he wished to do so, since at the time 14 was the minimum age for marriage under Alabama state law (it is now 16).

America has always allowed such child marriages, which happen mostly in conservative religious communities and rural areas. Yet, as in the rest of the world, the practice has become much less common. Whereas 23,500 minors got married in 2000, by 2010 the number had dropped to a little over 9,000, reflecting changing social norms, higher rates of school attendance for girls and a decline in marriage more generally. Virginia, Texas and New York have introduced laws in the past couple of years that restrict marriage to legal adults. Connecticut has banned marriage before the age of 16. In 11 other states legislation restricting child marriage is in the pipeline; six of these (Arizona, Florida, Maryland, Massachusetts, New Jersey and Pennsylvania) are considering a law to ban marriage under 18 with no exceptions.

Child marriage has become less common in America. But it still exists – The Economist