Sex and Reason.

• Author: Zelder, Martin

Richard Posner deserves substantial credit for advancing the public identity of modern law-and-economics scholarship. Thus, his latest book, Sex and Reason, may appear to the scholarly public and more casual readers as the definitive economic account of sex and sexuality. Posner declares his

ambition ... to present a theory of sexuality that both explains the principal

regularities in the practice of sex and in its social, including legal,

regulation and points the way toward reforms in that regulation - thus

a theory at once positive (descriptive) and normative (ethical).... [C]all

it the economic theory of sexuality. [pp. 2-3]

Unfortunately, Sex and Reason only occasionally achieves this worthy goal; often it provides an inaccurate representation of economic analysis and its implications.

Criticizing Richard Posner is hardly a novel exercise.(1) Criticism of Posner stems from the impression, held by American Economic Review editor Orley Ashenfelter, that "Posner is more of an economist than most economists,"(2) a point echoed by John Donohue and Ian Ayres in their review of Posner's Economic Analysis of Law: "While economics is a powerful and valuable tool in the analysis of legal and public policy issues, those who use it need an appreciation of its limitations."(3) On the contrary, in Sex and Reason, Posner is not as much of an economist as he should be; at various points he limits the scope of application for his model of economically rational behavior,(4) misunderstands economics,(5) and uses discomforting rhetoric largely unrelated to economics to discuss rape and gay and lesbian life.(6)

In addressing some of the problems found in Posner's analysis, I argue that the contention of Donohue and Ayres, that economic analysis should be limited to certain forms of human behavior,(7) is illfounded. Recent events have demonstrated the increasing acceptance of and enthusiasm for the application of economics to issues concerning the family, broadly construed, by economists and legal scholars. For example, the 1992 Nobel Prize in economics was conferred upon Gary Becker of the University of Chicago, the first person to use economics to analyze systematically major "familial" decisions such as marriage, childraising, and divorce.(8) Furthermore, the visibility of economic analysis of family law has increased in law reviews(9) and in the classroom.(10)

Outside the academy, economic analysis can explain individual choices regarding sex. For example, gay men have responded to the risk of AIDS by reducing the number of sexual partners and increasing condom use (p. 114). Economically rational behavior has also been exhibited by parent groups that have opposed free distribution of condoms to their high-school children; the groups have recognized that decreasing the risk of AIDS transmission or pregnancy reduces the cost of sex for those children.(11) Finally, even though many married people undoubtedly place a high value on sex with nonmarital partners, adultery rates are typically estimated to be far less than one hundred percent,(12) perhaps because adulterous sex is more costly than marital sex.

Posner offers his own worthy justifications for economic analysis of sexual behavior. He notes that "[s]tudents of sexuality recognize and deplore the lack of a rigorous and comprehensive scientific theory of human sexual behavior, but ... have not sought assistance in theories of rational choice" (p. 3). Economic analysis is the best way to study sexual behavior because it "incorporates, integrates, and transcends the perspectives, insights, and findings of the other theories of sexuality that can fairly be described as either scientific or social scientific" (p. 3). However, Posner writes that "[t]he uncompromising, the truly unassimilable rival of the economic theory ... is not scientific or social scientific; it is a heterogeneous cluster of moral theories," but "[t]hese theories ... are not convergent" (p. 3), suggesting the likely conflict of different moral prescriptions for sexual behavior.

At the same time, Posner is unwilling to proclaim the superiority of the economic approach because "moral and religious beliefs" that underlie moral theories "are irreducible to genuine social interests or practical incentives" and are thus (for purposes of comparison) "incompatible with the broadly scientific outlook that informs the approaches [he] seek[s] to recast in the mold of economics" (p. 4). Nevertheless, in assessing the degree of social acceptance of his approach, Posner recognizes that "[a]n approximation to a scientific, nonmoral outlook on sexuality is highly influential today in northern Europe, especially Sweden, Denmark, and the Netherlands, as well as in Japan and other areas of East Asia," although this approach is "resisted most strongly by a diverse group of nations that includes the United States" (p. 4).

Accepting the singular potential of economics to explain sex, Posner's distortions and errors of economic analysis create the danger that many readers will perceive Sex and Reason as the ultimate application of economic analysis to sexual-familial issues, rather than a significantly flawed initial attempt.(13) Certainly, Posner's book is crucial because it addresses many issues that economists have virtually ignored. Indeed, the book is catalytic in eliciting systematic evaluation of some questions, in print, that had previously almost exclusively been pursued in the classroom, outside the brighter light of public scrutiny.(14) The value of carefully applying economic reasoning to sexual behavior is not inherent or aesthetic; rather, it is pragmatic because such analysis can serve "as a foundation for proposing reforms in law and public policy" (p. 7). Posner emphasizes this foundation, which is the "positive (descriptive)" analysis of sex, because "[s]ound reform depends on knowledge to a degree that lawyers do not always appreciate" (p. 7). Posner focuses less, and less successfully, on "normative (prescriptive)" evaluations (p. 7).

It is important, then, not to neglect the value of Posner's explorations, even if they sometimes lead one astray. Sex and Reason provides a rough, incomplete map to the territory of economic analysis of sexual-familial issues. As such, the book is useful to both scholars and lawmakers in identifying many sexual topics significant enough to justify economic analysis and in sketching out the specifics of this analysis for many of these topics. This review evaluates Posner's intellectual cartography, particularly his three identifiable realms of discourse - positive analysis of sexual behavior and sexual lawmaking, normative assessment of laws regulating sex, and infelicitous rhetoric on issues such as rape and "homosexuality" that are essentially unfounded in economic analysis.

1. Posner's Positivism

   1. Positive Analysis of Sexual Lawmaking

      More than any other law-and-economics scholar, Posner has attempted to construct hypotheses that describe the pattern of legal rules limiting societies. This orientation aligns Posner, methodologically, with George Stigler and the Chicago School of regulation, which emerged from the public choice movement.(15) Consequently, the most prominent thread of Posner's positive analysis in Sex and Reason is the formulation of theories that explain laws governing sex; his other positive pursuit is to explain sexual behavior.

      Positive theories such as these rest on the assumption that individual actors - judges, in the first case, sexual "consumers" in the second - are economically rational. Economic rationality means that an actor makes choices in a way that improves her own welfare ("utility"). Rational actors who maximize their own utility are also acting in a manner that maximizes the welfare of the entire society - in other words, they are taking economically efficient actions. But economic efficiency results from self-interested rational behavior only when individual actors participate in competitive markets free of any "market failures." Judges making decisions, however, are not ostensibly subject to the mechanisms of a competitive market free of market failures; thus, these judges, acting in their own self-interest, are not necessarily or even probably making efficient decisions.

      Indeed, the deduction that law promotes efficiency receives only qualified theoretical support in the law-and-economics literature.(16) In other writing, Posner contends that "judges seek to impose their personal preferences and values on society,"(17) although these values will often be shaped by "a strong social consensus in favor of the use of the efficiency criterion."(18) Imputing an efficiency motive to judges ventures beyond the economist's fundamental assumption that judges are rational and thus may or may not be efficient in their holdings. In effect, Posner attaches a much more restrictive assumption to the behavior of judges than he does to consumer behavior, assuming "only" rational choices but not necessarily efficient outcomes for consumers.

      Despite the limited theoretical support for the notion that laws promote efficiency, Posner in Sex and Reason regards efficiency as a primary factor explaining the content of sex laws. Only after thirty-five pages of his thirty-eight-page chapter, "Optimal Regulation of Sexuality," does Posner acknowledge that "[ilt would be heroic to contend that all sex laws can be explained on either efficiency or distributive grounds" (p. 217; emphasis added). In trying to fulfill this goal in much of his book, however, Posner misleads the reader into believing that this enterprise's outcome is the barometer of the success of law and economics.

      Law and economics has been a valuable discipline for legal scholarship, and Posner's admission that it cannot fulfill a "heroic" mandate does not indicate that other analytical means are needed to study the law of sexual behavior. It is not surprising that Posner finds many...