Powerful currents have reshaped the structure of families over the last century. There has been (i) a dramatic drop in fertility and greater parental investment in children; (ii) a rise in married female labor-force participation; (iii) a significant decline in marriage and a rise in divorce; (iv)...

Societies socialize children about sex. This is done in the presence of peer-group effects, which may encourage undesirable behavior. Parents want the best for their children. Still, they weigh the marginal gains from socializing their children against its costs. Churches and states may...