Individual views within a given society can vary greatly, with expectations ranging from total abstinence to frequent casual sex. These views are dependent on the holders' value system, as formed by their parents, religion, friends, experiences, and in many cases the media. Unmarried cohabitation and births outside marriage have increased in many Western countries during the past few decades. Economist Jeremy Greenwood (2019, Chp. 4) discusses how technological progress in contraception led to a rise in premarital sex and less stigmatization by parents, churches, and governments. He argues that singles weigh the cost (a potential pregnancy) and benefit of premarital sex. As contraception improved the cost of premarital sexual activity fell. Parents and social institutions also weigh the cost and benefit of socialization. Technological improvement in contraception reduced the benefit of socialization because premarital sexual activity was no longer as risky in terms of unwanted pregnancies, which placed a strain on parents and social institutions. As a result, there was social change.
