As you report, the research by Dean Busby and his colleagues at Brigham Young University in Utah suggests that people who eschew premarital sex have better relationships once married (“The Waiting Game,” January 22, 2011). They recruited more than two-thousand people of different ages and different marriage lengths, and asked them to complete an online questionnaire with nearly three-hundred questions. As you point out, the main finding of the research may only show that people who are capable of agreeing to delay their first sexual encounter may also be better at agreeing on everything else. This would show correlation rather than causation. What about people who stay together but never marry, though? With the decline of marriage as an institution, their numbers are growing across the developed world, and the law rightly treats their relationships just as it treats marriage. Relationships like these make the very notion of premarital sex obsolete. Nay, archaic. Of course, it will take a while for Utah and many other states in the American interior to catch up with the developed world.