Russell Korobkin (UCLA) provocatively declares the ultimate victory of behavioral law and economics over neoclassical economics:

I am declaring victory in the battle for the methodological soul of the law and economics discipline. There is no need to continue to pursue the debate between behavioralists (that is, proponents of incorporating insights previously limited to the discipline of psychology into the economic analysis of legal rules and institutions) and the defenders of the traditional faith in individual optimization as a core analytical assumption of legal analysis.

Behavioral law and economics wins.  And its not close.  Korobkin continues:

[T]he battle to separate the economic analysis of legal rules and institutions from the straightjacket of strict rational choice assumptions has been won, at least by and large.  The fundamental methodological assumption of rational-choice economics, that individual behavior necessarily maximizes subjective expected utility, given constraints, has been largely discredited as an unyielding postulate for the analysis of legal policy.  Yes, such an assumption, even if inaccurate, simplifies the world, but it does so in an unhelpful way, much in the way that it is unhelpful for a drunk who has lost his car keys in the bushes to search under the streetlamp because that is where the light is.

The paper is remarkable on many levels, few of them positive.   I understand Professor Korobkin is trying to be provocative; in this he succeeds.  I — for one — am provoked.  But one problem with claims designed to provoke is that they may sacrifice other virtues in exchange for achieving the intended effect.  In this case, humility and accuracy are the first — but not the last – to go.   Indeed, Korobkin begins by acknowledging (and marginalizing) those would deny victory to the behaviorists while magnanimously offering terms of surrender:

Not everyone has been won over, of course, but enough have to justify granting amnesty to the captured and politely ignoring the unreconstructed.

Unreconstructed.  I guess I’ll have to take that one.  Given the skepticism I’ve expressed (with Douglas Ginsburg) concerning behavioral law and economics, and in particular, the abuse of the behavioral economics literature by legal scholars, it appears capture is unlikely.   Indeed, Judge Ginsburg and I are publishing a critique of the behavioral law and economics movement — Behavioral Law and Economics: Its Origins, Fatal Flaws, and Implications for Liberty — in the Northwestern Law Review in January 2012.   A fuller development of the case for skepticism about behavioral law and economics can wait for the article; it suffices for now to lay out a few of the most incredible aspects of Korobkin’s claims.

Perhaps the most incendiary aspect of Korobkin’s paper is not a statement, but an omission.  Korobkin claims that rational choice economics has been “largely discredited as an unyielding postulate for the analysis of legal policy” – and then provides no citation for this proposition.  None.  Not “scant support,” not “conflicting evidence” — Korobkin dismisses rational choice economics quite literally by fiat.  We are left to infer from the fact that legal scholars have frequently cited two important articles in the behavioral law and economics canon (the 1998 article A Behavioral Approach to Law and Economics by Christine Jolls, Cass Sunstein and Richard Thaler and Law and Behavioral Science: Removing the Rationality Assumption from Law and Economics by Korobkin and Tom Ulen) that the behavioral approach has not only claimed victory in the marketplace for ideas but so decimated rational choice economics as to leave it discredited and “unhelpful.”  One shudders to consider the legion of thinkers chagrinned by Korobkin’s conclusive declaration.

Oh, wait.  The citations prove the behavioral law and economics is popular among legal scholars — and that’s about it.  I’ve no doubt that much is true.  If Korobkin’s claim was merely that behavioral law and economics has become very popular, I suppose that would be a boring paper, but the evidence would at least support the claim.  But the question is about relative quality of insight and analysis, not popularity.  Korobkin acknowledges as much, observing in passing that “Citation counts do not necessarily reflect academic quality, of course, but they do provide insight into what trends are popular within the legal academy.”   Undaunted, Korobkin moves seemlessly from popularity to the comparative claim that behavioral law and economics has “won” the battle over rational choice economics.   There is no attempt to engage intellectually on the merits concerning relative quality; truth, much less empirical validation, is not a mere matter of a headcount.

Even ceding the validity citations as a metric to prove Korobkin’s underlying claim — the comparative predictive power of two rival economic assumptions — what is the relative fraction of citations using rational choice economics to provide insights into legal institutions?  How many cites has Posner’s Economic Analysis of Law received?  Where is the forthcoming comparison of articles in the Journal of Law and Economics, Journal of Legal Studies, Journal of Political Economy, Journal of Law, Economics, and Organization, American Economic Review, etc.?  One might find all sorts of interesting things by analyzing what is going on in the law and economics literature.  No doubt one would find that the behaviorists have made significant gains; but one expecting to find rational choice economics has been discredited is sure to to be disappointed by the facts.

Second, notice that the declaration of victory comes upon the foundation of citations to papers written in 1998 and 2000.  The debate over the law and economics of minimum resale price maintenance took nearly a century to settle in antitrust law, but behavioral law and economics has displaced and discredited all of rational choice economics in just over a decade?  The behavioral economics literature itself is, in scientific terms, very young.  The literature understandably continues to develop.  The theoretical and empirical project of identifying the conditions under which various biases are observed (and when they are not) is still underway and at a relatively early point in its development.  The over-reaching in Korobkin’s claim is magnified when one considers the relevant time horizon: impatience combined with wishful thinking is not a virtue in scientific discourse.

Third, it is fascinating that it is consistently the lawyers, and mostly law professors, rather than the behavioral economists, that wish to “discredit” rational choice economics.  Similarly, rational choice economists generally do not speak in such broad terms about discrediting behavioral economics as a whole.  Indeed, behavioral economists have observed that “it’s becoming clear that behavioral economics is being asked to solve problems it wasn’t meant to address.  Indeed, it seems in some cases that behavioral economics is being used as a political expedient, allowing policymakers to avoid painful but more effective solutions rooted in traditional economics.”  There are, of course, significant debates between theorists concerning welfare implications of models, from empiricists interpreting experiments and field evidence.  It is the law professors without economic training that want to discredit a branch of economics.  It is important to distinguish here between behavioral economics and behavioral law and economics, and between rational choice economics and its application to law.  No doubt there are applications of rational choice economics to law that overreach and warrant deserved criticism; equally, there are abuses of behavioral economics in the behavioral law and economics literature.  It is a very productive exercise, and one in which law professors might have a comparative advantage, to identify and criticize these examples of overreaching in application to law.   But with all due respect to Professor Korobkin, if rational choice economics is going to be discredited – a prospect I doubt given its success in so many areas of the law – some economists are going to have to be involved.

Fourth, in the midst of declaring victory over rational choice economics, Korobkin doesn’t even bother to define rational choice economics correctly.  Korobkin writes:

To the extent that legal scholars wish to premise their conclusions on the assumption that the relevant actors are perfect optimizers of their material self-interest, they bear the burden of persuasion that this assumption is realistic in the particular context that interests them.

Elsewhere, Korobkin writes:

My central thesis, which runs through the three parts of the article to follow, is that now that law and economics has discarded the “revealed preferences” assumption of neoclassical economics – that individual behavior necessarily maximizes subjective expected utility . . .

This isn’t the rational choice argument; this barely suffices as a caricature of the rational choice assumption underlying conventional microeconomic analysis.  Korobkin falls victim to the all-too-common misunderstanding that the rational choice assumption is a descriptive assumption about each individual’s behavior.  Not only is that obviously incorrect, and I suspect Korobkin knows it; anyone with even a passing familiarity with rational choice literature realizes that a host of economists — Friedman, Becker, Stigler, and Alchian, to name a few — have long been interested in, understood, and incorporated irrational economic behavior into microeconomics.  The rational choice assumption has never been about describing the individual decision-making processes of economic agents.  Perhaps a model with a different assumption, e.g. that all individuals exhibit loss aversion or optimism bias (or half of them, or a quarter, or whatever), will offer greater predictive power.  Perhaps not.  Economists all agree that predictive power is the criterion for model selection.   That is the right debate to have (see, e.g., here), not whether law professors find uses for the behavioral approach to argue for various forms of paternalistic intervention – and, for note, is still the case that this literature is used nearly uniformly for such purposes by law professors.  Korobkin’s method of declaring methodological victory on the behalf of behavioral law and economics while failing to accurately describe rational choice economics is a little bit like challenging your rival to “take it outside,” and then remaining inside and gloating about your victory while he is waiting for the fight outside.

Korobkin defends his provocative declaration of victory with the argument that it allows him to “avoid an extended discussion” of a number of claims he has already deemed appropriate to dismiss (mostly through conventional strawman approaches) in favor of focusing on new and exciting challenges for the behaviorists.  I offer two observations on the so-called benefits of declaring victory while the battle is still being waged.  The first is that avoiding evidence-based debate is a bug rather than a feature from the perspective of scientific method.  The second is a much more practical exhortation against premature celebration: you can lose while you admire the scoreboard.  Anyone who has ever played sports knows it is best to “play the whistle.”

One final observation.  I recall from Professor Korobkin’s website bio that he is a Stanford guy.  You’d think he’d be a little bit more sensitive to the risk of losing the game while the band prematurely celebrates victory.