Alex Stein, Professor of Law

The Distortionary Effect of Evidence on Primary Behavior
In this Essay, we analyze how evidentiary concerns dominate actors’ behavior. Our findings offer an important refinement to the conventional wisdom in law and economics literature, which assumes that legal rules can always be fashioned to achieve socially optimal outcomes. We show that evidentiary motivations will often lead actors to engage in socially suboptimal behavior when doing so is likely to increase their likelihood of prevailing in court. Because adjudicators must base decisions on observable and verifiable information—or, in short, evidence—rational actors will always strive to generate evidence that can later be presented in court and increase their chances of winning the case regardless of the cost they impose on third parties and society at large. Accordingly, doctors and medical institutions will often refer patients to undertake unnecessary and even harmful examinations just to create a record that they went beyond the call of duty in treating them. Owners of land and intellectual property may let harmful activities continue much longer than necessary just to gather stronger evidence concerning the harm they suffer. And even the police will often choose to allow offenders to carry out crimes in order to improve the chance of a conviction. The effect we identify is pervasive. It can be found in virtually all areas of the law. Furthermore, there is no easy way to eliminate or correct it. It should be noted, however, that the evidentiary phenomenon we discuss also has a positive side effect: it reduces adjudication costs for judges and juries and improves the accuracy of court processes.  In some cases, this improvement will exceed the social cost stemming from actors’ suboptimal behavior.  In other contexts, however, the social cost will far outweigh the benefit.

The Distortionary Effect of Evidence on Primary Behavior, 124 Harvard Law Review 518-548 (2010) (with Gideon Parchomovsky) download


Strategic Enforcement
Doctrine and scholarship recognize two basic models of enforcing the law: the comprehensive model, under which law-enforcers try to apprehend and punish every violator within the bounds of feasibility; and the randomized model, under which law enforcers economize their efforts by apprehending a small number of violators and heightening their penalties so as to make violations unattractive. This Article supplements this list of options by developing a strategic model of law enforcement. Under this model, law enforcers concentrate their effort on the worst, or most rampant, violators at a given point in time while leaving all others unpunished. This enforcement strategy will force violators into a cascaded retreat: to avoid detection as one of the worst violators, every individual wrongdoer will bring the level of his unlawful activity down to the point of inconspicuousness—a process that will repeat itself several times to society’s benefit. This Article identifies the circumstances that call for the strategic model’s adoption and illustrates the model’s potential as an enforcement tool in diverse areas of the law that include employment discrimination, election districting, and copyright protection.

Strategic Enforcement, 95 Minnesota Law Review 9-58 (2010) (with Margaret H. Lemos) download


THE OVERENFORCEMENT PARADIGM

Overenforcement of the law occurs when the total sanction suffered by the violator of a legal rule exceeds the amount optimal for deterrence. Overenforcement sometimes generates overdeterrence that cannot be remedied through the adjustment of substantive liability standards or penalties in light of operational and expressive constraints. When that happens, the legal system can counteract the effects of overenforcement by adjusting evidentiary or procedural rules to make liability less likely (ex ante). This framework -- the overenforcement paradigm -- illuminates previously unnoticed features of various evidentiary and procedural arrangements. It also provides a useful analytical and prescriptive tool for creating balanced incentives in cases in which overenforcement is present.

Overenforcement, 93 Georgetown Law Journal 1743 (2005) (with Richard A. Bierschbach)  download

ASYMMETRIC AMBIGUITY AVERSION FOILS CRIMINAL JUSTICE

Ambiguity aversion is a person's rational attitude towards probability's indeterminacy. When a person is averse towards such ambiguities, he increases the probability of the unfavorable outcome to reflect that fear. This observation is particularly true about a criminal defendant who faces a jury trial. Neither the defendant nor the prosecution knows whether the jury will convict the defendant. Their best estimation relies on a highly generalized probability that attaches to a broad category of similar cases. The prosecution, as a repeat player, is predominantly interested in the conviction rate that it achieves over a long series of cases. It therefore can depend on this general probability as an adequate predictor of this rate. The defendant only cares about his individual case and cannot depend on this general probability. From the defendant's perspective, his individual probability of conviction is ambiguous. The defendant consequently increases this probability to reflect his fear of that ambiguity. Because most defendants are ambiguity-averse, while the prosecution is not, the criminal process systematically involves and is thoroughly affected by asymmetric ambiguity-aversion.

Asymmetric ambiguity-aversion foils criminal justice. The prosecution can exploit it by forcing defendants into plea bargains that are both inefficient and unfair. Because plea bargain is a predominant method of case-disposition across the United States, this exploitation opportunity is particularly pernicious. The legal system ought to eliminate it.

Two Fifth Amendment doctrines -- the rule against double jeopardy and the grand jury review of indictments -- have the effect of mitigating this problem. The rule against double jeopardy sets a pro-defendant system of asymmetric rights to appeal. This system reduces the probability of conviction for all defendants, regardless of the merits. This probability reduction offsets -- but not eliminates -- the upward adjustment that an ambiguity-averse defendant introduces into his probability of conviction. Grand jury review disambiguates the defendant's probability of conviction when he is informed about the grand jurors' voting score. This disambiguation is only partial, though, because grand jurors are authorized to indict upon mere showing of a "probable cause."

The prevalent constitutional doctrine should therefore be modified by giving a defendant the right to choose between a bench trial and a trial by jury. Judges are repeat institutional players that credibly commit themselves to reasons for decisions that are evenhanded, known and institutionally approved. This commitment is induced not only by the judges' fear of reversal and other career-related repercussions, but also by the defendant's constitutional entitlement to a trial by jury. For judges, jury trial is a time-consuming and effort-intensive process with virtually no career-enhancing returns. Judges therefore strongly prefer a bench trial over a trial by jury. To actualize this preference, judges need systematically to deliver evenhanded decisions that follow the institutionally approved reasons. This makes judges' decisions predictable. The defendant's probability of being convicted by a judge in a bench trial thus becomes unambiguous, which neutralizes the prosecution's ambiguity-exploiting pressure in plea bargaining.

Empirical data confirm these findings. Specifically, they identify three major trends. First, bench trials are prevalent in jurisdictions featuring high trial rates, generated by a non-meticulous selection of cases for prosecution. Second, the rate of acquittals in bench trials is much higher than in trials by jury. The defendants' ambiguity-aversion is the most plausible explanation of these trends. Defendants with real prospects for acquittal have much to lose and are therefore unwilling to depend upon unpredictable juries. Finally, there is a demand for jury-consulting services and no discernible market for judge-consulting services. Litigants are willing to pay for information predicting the outcomes of jury trials and are generally unwilling to pay for information predicting judges' decisions in bench trials. This leads to the conclusion that ambiguity aversion is particularly problematic in trials by jury.