Narrator: What if the Sexual Revolution of the 1960s was driven less by a cultural awakening and more by the falling price of a single commodity: sex? What if the hookup culture on college campuses isn't a sign of moral decay, but a predictable outcome of simple supply and demand? And what if the decision to cheat on a partner can be analyzed with the same rational cost-benefit logic used to evaluate a business investment? These questions may seem jarring, but they lie at the heart of a provocative field of study that applies the "dismal science" of economics to our most intimate affairs.

In the book Dollars and Sex: How Economics Influences Sex and Love, Dr. Marina Adshade pulls back the curtain on the invisible economic forces that shape our decisions about love, marriage, and sexuality. She argues that nearly every choice we make in this domain, from a first date to a divorce, is better understood when viewed through an economic lens. The book provides a framework for understanding the markets for sex and love, revealing that our most personal choices are deeply influenced by the same principles that govern financial markets.

Narrator: The central premise of Dollars and Sex is that our romantic and sexual lives operate as a series of markets. In these markets, individuals are both buyers and sellers, trading on a complex set of assets that include physical attractiveness, intelligence, earning potential, kindness, and youth. The "price" isn't paid in cash, but in the opportunity costs we accept—the partners and experiences we forego when we choose to be with one person.

Adshade explains that economists use a concept called "revealed preference" to understand these markets. Instead of asking people what they want, they observe the choices people actually make. This data-driven approach avoids the gap between what people say and what they do. For example, data from online dating and speed-dating events consistently reveals that while people may claim to be open-minded, their actual choices show strong preferences for partners of the same ethnicity and educational background. By analyzing these choices, the book demonstrates that our romantic pursuits are not random or purely emotional; they are rational responses to the market conditions we find ourselves in.

Narrator: The book reframes the Sexual Revolution not as a sudden cultural shift, but as a rational response to a change in price. Before the widespread availability of effective contraception, the cost of premarital sex for women was extraordinarily high, including social stigma and the significant risk of unwanted pregnancy. The pill dramatically lowered this cost. Suddenly, the benefits of premarital sex began to outweigh the risks for millions of women, and behavior changed accordingly.

This cost-benefit analysis continues to shape sexual behavior today, particularly among the young. The book presents the harrowing story of Sarah, a first-year college student who, after a night of binge drinking, has unprotected sex and becomes pregnant. Her story illustrates the devastating consequences that can occur when the perceived costs of sex are temporarily lowered by alcohol. Adshade connects this to a wider campus dynamic. On campuses where women outnumber men, a "buyer's market" for sex emerges. With a surplus of women, men hold more market power and can demand casual sex at a lower "price"—that is, with less commitment. Data shows that on these campuses, women are less likely to have a steady boyfriend and more likely to engage in sexual acts they dislike, all as a rational adaptation to a competitive market.

Narrator: In the modern era, the search for a long-term partner has moved online, creating what economists call a "thick market" with millions of participants. However, Dollars and Sex argues this isn't always an advantage. Adshade uses a clever analogy of a pastry shop. When faced with overwhelming choice, we simplify by eliminating entire categories, like "no cookies" or "no chocolates." Online dating encourages this with filters for age, height, and income. The problem is that unlike in the pastry shop, where you can still see the delicious macaron you almost missed, online filters make potential matches disappear completely, potentially screening out a perfect partner based on superficial criteria.

Once a partner is found, the book explains that marriage, from an economic standpoint, is a firm dedicated to the efficient production of household goods and services, including love, companionship, and children. The key to this efficiency is "comparative advantage." The book illustrates this with the story of Jordan and Alex, a couple dividing evening chores. Even if Jordan is faster at both cleaning the kitchen and putting their baby to bed (an absolute advantage), it’s more efficient for the household if they specialize. If Jordan is relatively better at bedtime stories and Alex is relatively better at dishes, they gain time and efficiency by dividing tasks accordingly. This principle of specialization is a primary economic driver for forming a partnership.

Narrator: Why is monogamy the dominant form of marriage in wealthy nations, even when high income inequality means some men could theoretically support multiple wives? The book offers an economic explanation. In knowledge-based economies, parents desire "high-quality" children, which requires significant investment in education. This makes an educated, intelligent partner more valuable than multiple less-educated ones. Furthermore, as women have become more educated and economically independent, they have gained significant bargaining power in the marriage market and are far less likely to accept a polygynous arrangement.

Even within monogamous marriages, the temptation of infidelity persists. Adshade analyzes this not as a simple moral failure but as another economic decision. A person weighs the benefits of an affair—such as satisfying a biological drive for novelty (the "Coolidge Effect") or finding emotional connection outside an unhappy marriage—against the expected costs. These costs include the probability of being caught multiplied by the severity of the consequences, which can range from divorce and financial ruin to social stigma. Power also plays a key role. While higher income doesn't necessarily predict infidelity in men, a position of power increases the likelihood for both men and women, not because they are less moral, but because power brings more opportunities and confidence.

Narrator: The book demonstrates that our economic outlook profoundly influences our sexual choices throughout our lives. For teenagers, Adshade argues that high income inequality creates a "culture of despair." In communities with few opportunities, the long-term economic cost of a teen pregnancy feels less significant, making risky sexual behavior a more rational choice. This is illustrated through the story of Troy, a boy from a low-income neighborhood whose family sees no value in him taking college-prep courses, signaling a deep pessimism about his future.

At the other end of life, the market dynamics are completely different. Increased longevity, better health, and online dating have created a booming late-in-life market for sex and love. Here, traditional assumptions are often inverted. The book tells the story of an older man who ends a relationship because, as he puts it, "She is only using me for sex." He was seeking companionship, while his female partner was more interested in a casual relationship. This flips the stereotype that older men are only seeking youth and sex. For many older women, financial independence gives them the power to be highly selective, choosing to remain single rather than settling for an inferior partner.

Narrator: The single most important takeaway from Dollars and Sex is that our most intimate decisions are not made in a vacuum. They are profoundly shaped by the invisible hand of the market. The supply of eligible partners, the cost of contraception, the rate of unemployment, and the level of income inequality in our society all exert a powerful influence on who we love, how we love, and the rules we live by. The book forces us to see that our personal lives are inextricably linked to the broader economic systems we inhabit.

Ultimately, the most challenging idea Adshade presents is that our romantic freedom may be more of an illusion than we care to admit. We are all players in a market, and our choices are constrained by our market value and the options available to us. It leaves us with a powerful question for self-reflection: The next time you make a decision about your love life, can you identify the economic forces at play?