Add to ORKGPublicado por Economia de Avant Garde. 2009. UC3M Working paper. nº 9In 1900 only six percent of unwed females engaged in premarital sex. Now, three quarters do. The sexual revolution is studied here using an equilibrium matching model, where the costs of premarital sex fall over time due to technological improvement in contraceptives. Individuals di¤er in their desire for sex. Given this, people tend to circulate in social groups where prospective partners share their views on premarital sex. To the extent that a society`s customs and mores reffect the aggregation of decentralized decision making by its members, shifts in the economic environment may induce changes in what is perceived as culture