Comment: Evolutionary Theories of Common Law Efficiency: Reasons for (Cognitive) Skepticism

Abstract:     
This comment critically examines evolutionary models of the common law in the light of behavioral theory. To the extent that the common law assumes the characteristics that judges strive to impart upon it, their efforts are doomed to succeed imperfectly, as a consequence of judges' bounded rationality. On the other hand, several different but related models of common law dynamics posit that judge-made law tends ineluctably in the direction of economic efficiency as a consequence of blind, evolutionary mechanisms operating independently of judges' predilections. Hence, evolutionary models suggest the possibility that over time, the process of lawmaking can transcend the bounded rationality of lawmakers and achieve a degree of efficiency that advertent efforts of design could not.

Nevertheless, this comment concludes that evolutionary models of common law dynamics offer no escape from the bottleneck of bounded rationality. Although the states of minds of judges are irrelevant to those models, they depend instead upon the assumption that other participants in the judicial process - litigants and their attorneys - are rational decision-makers. When we assume instead that litigants and attorneys are susceptible to the same cognitive frailties that human beings generally share, the models break down, or at least become adulterated by noise that weakens the evolutionary pressures that they hypothesize.

The difficulties with those models do not disappear even when we relax the assumption that the common-law system within which rules are formulated is fixed in its present structure. A historical alternative to the current structure that one scholar has hypothesized to have been particularly productive of efficient rules is in fact degraded by the same cognitive frailties. Nor can we predict that meta-evolutionary processes of competition between legal systems will lead the principles of jurisprudence in the direction of a system most likely to generate efficient rules.

Working Paper Series