Of fruitcakes and patriot games

Georgetown Law Journal, Jul 2002 by Gilman, Daniel

INTRODUCTION

It verges on the circular to say that legal scholars typically focus their studies on the law. But recent years have seen the legal academy pay increasing attention to nonlegal constraints on human behavior; that is, to the study of social norms.1 And perhaps that is not surprising after all. For legal constraints-as a species-surely had a genesis in less formal means of controlling human impulses just as particular laws continue to derive from various customs and moral standards.2 Myriad norms, mores, customs, and customary understandings play a complex role in the law, from informing the "reasonable man" and "reasonable person" standards in tort law (and elsewhere), to filling in the normal and customary practices that vary across trades in commercial law. Interesting and complex borderline cases arise as well, cases in which nonlegal standards increasingly resemble law, both formally and substantively. Consider the very law-like, formal, written, legally enforceable strictures of a private-side regulatory agency, such as NASD, Inc., as it constrains the behavior of securities dealers in the United States. It plays a role the law requires some private agency to play, under the supervision of the Securities and Exchange Commission.3

Some of the more interesting legal studies of social norms to date have come from the perspective of law and economics.4 Perhaps this, too, ought not to be surprising, as law and economics carries the considerable methodological tools of an independent discipline, tools that were not developed with a parochial eye toward legal phenomena and that have proved powerful in modeling diverse nonlegal phenomena quite apart from the study of social norms. Eric Posner's recent book, Law and Social Norms, may be the most ambitious such effort to date.

While previous studies focused on particular norms, or sets of related norms governing narrowly defined communities, Posner seeks to explain norms in general.6 Moreover, while previous studies applied various conceptual tools borrowed from economic analysis, Posner seeks an especially generative application of signaling theory-or a particular variation on signaling theory-- simpliciter. That is, Posner undertakes a specific "methodological commitment" to explain a broad spectrum of nonlegal constraints on human behavior across cultures and throughout history as manifestations of a particular kind of signaling behavior.

The book is about what Posner calls "nonlegal mechanisms of cooperation."8 In brief, Posner argues that social norms allow parties to solve a particular sort of repeat prisoner's dilemma game that is seen to describe a general condition of putatively cooperative behavior. Social norms are said to provide this solution by offering a means of signaling to other players that one is a good cooperative partner. One sends the signal by compliance with social expectations, and sometimes by persecution of those who fail to comply. More precisely, signaling behavior-compliance with the norm-is seen to be an effective proxy for having a low discount rate, and having a low discount rate is, in turn, seen as an effective proxy for being a good partner in diverse (presumably not too short-term) cooperative ventures.

Posner's model is supposed to explain such various phenomena as giftgiving, flag-waving, charivari, courtship rituals, table manners, and visible displays of racial prejudice. That is the scope of its theoretical ambition: to describe myriad nonlegal constraints on human behavior through the application of a simple game-theoretic model and, in so doing, to supplant, effectively, a number of alternative disciplinary approaches that may be-and in some cases have long been-concerned with explaining just those phenomena.

I think, in the end, that Posner does not succeed. Much of the discussion of various customary practices is quite interesting, but much of it rings false. More generally, I do not think that Posner's signaling model offers adequate explanation for some of the central phenomena it seeks to explain. Repeatedly, it appears that the cost structure of Posner's signals cannot be right-the signals coming too cheap or too dear-if signaling can, qua rational choice theory, explain the norms in question. We may take it as troubling, too, that we can never tell for sure; there's enough play in the model that it may not generate adequately specific predictions for careful evaluation in any case. It may or may not be testable in principle, but there are no clear empirical predictions in the book. Moreover, no obvious tests present themselves. Correspondingly, it is not entirely clear what a social norm is. Posner acknowledges this, but it seems a defect nonetheless in a book-length theoretical treatment of some phenomenon that the basic explanandum-the central phenomenon the theory seeks to explain-is so ill-defined.9

Finally, I am not convinced that Posner's norms describe a natural kind; that is, I suspect that the cases Posner takes under the umbrella of "social norms" are fundamentally diverse and that there is no simple empirical model-on the order of Posner's signaling game-that adequately accounts for all of them. I think that Posner is unduly quick to dismiss other perspectives on some of these phenomena and is unduly charitable in describing the relative advantages of his approach. To be fair, Posner acknowledges most of these shortcomings, but readers may be dissatisfied nonetheless with the theory as it stands.