Same Old, Same Old: Scientific Evidence Past and Present

For over twenty years, and particularly since the Supreme Court\u27s Daubert\u27 decision in 1993, much ink has been spilled debating the problem of scientific evidence in the courts. Are jurors or, in the alternative, judges qualified to assess scientific reliability? Do courts really need to be concerned about junk science ? What mechanisms can promote better decision making in scientific cases? Even a cursory scan of the literature shows the recent explosion of interest in these issues, precipitating new treatises, hundreds of articles, and countless conferences for judges, practitioners, and academics

Fighting Legal Innumeracy

An old joke quips that lawyers go to law school precisely because they never liked math or were never good at math – and that therefore medical school (or these days, Wall Street) was not an option. While this tired joke may have a kernel of truth, I want to suggest that we should be very wary of internalizing it. Numeracy is a fundamental skill for any intelligent, engaged participant in society, and we lawyers ignore it at our peril. The term “innumeracy” was coined by Douglas Hofstadter in a 1982 article in Scientific American and perhaps made famous by John Allen Paulos. In his book, Paulos observes that while readers frequently condemn grammatical errors, wild mathematical ones often pass undetected. If this observation is true for anybody, it is definitely true for lawyers. Playing gotcha with typos is practically the official sport of the bench and bar. Yet, lawyers and courts notoriously make incorrect numerical calculations – sometimes caught, sometimes not – but generally without the same snarky rebukes.The primary focus of Hoftstadter and Paulos, however, is on the inability of the public to grapple with numbers. Accordingly, they stress the importance of estimation and orders of magnitude. For example, just how big is a billion dollars, or a trillion dollars? Or more trivially – though not so for aspiring management consultants – how many ping-pong balls will fit into a backyard swimming pool? I want to recast the numeracy problem to be a bit more lawcentric. For lawyers, numeracy should be less about numbers per se and more about statistical inference or how to interpret and understand scientific or social scientific studies

Changing Scientific Evidence

A number of high-profile toxic tort cases, such as silicone breast implants, have followed a familiar and disturbing path: Early studies suggest a link between a suspected substance and a particular illness. Based on these initial studies, lawsuits are brought and juries award large judgments to various plaintiffs. Then later, more comprehensive studies find no evidence of a causal link. How should the legal system cope with this problem in which new scientific evidence calls into question previous findings of liability? These erroneous judgments seriously harm social welfare and legitimacy. Beneficial products are needlessly discontinued or are made more expensive, and public confidence is undermined by decisions entirely at odds with science. This Article observes that in a subset of cases, the legal system\u27s traditional emphasis on speedy dispute resolution and finality is brought into direct conflict with science\u27s culture of incremental study and constant reevaluation. The resulting timing mismatch is at the root of the changing scientific evidence problem. To alleviate it, the Article suggests the use of two alternative procedural devices. Courts could stay proceedings for a fixed period of time when additional confirmatory studies were anticipated. Alternatively, courts could address changing scientific evidence after final judgment through an expansion of post-judgment relief. Either of these options would enable courts to be more accommodating to the scientific process, while simultaneously spurring scientists to better serve legal inquiry

Completing the Quantum of Evidence

In Evidentiary Irony and the Incomplete Rule of Completeness, Professors Daniel Capra and Liesa Richter comprehensively catalog the many shortcomings in current Federal Rule of Evidence 106 and craft a compelling reform proposal. Their proposal admirably solves the identified problems, keeps the rule reasonably succinct, and furthers the accuracy and fairness goals of the rules of evidence. In this Response, we focus on Capra & Richter\u27s proposal to formally recognize a trumping power in Rule 106, which would allow an adverse party to offer a completing statement even if it would be otherwise inadmissible under the rule against hearsay

Selected Legal Applications for Bayesian Methods

This dissertation offers three contexts in which Bayesian methods can address tricky problems in the legal system. Chapter 1 offers a method for attacking case publication bias, the possibility that certain legal outcomes may be more likely to be published or observed than others. It builds on ideas from multiple systems estimation (MSE), a technique traditionally used for estimating hidden populations, to detect and correct case publication bias. Chapter 2 proposes new methods for dividing attorneys' fees in complex litigation involving multiple firms. It investigates optimization and statistical approaches that use peer reports of each firm's relative contribution to estimate a "fair" or consensus division of the fees. The methods proposed have lower informational requirements than previous work and appear to be robust to collusive behavior by the firms. Chapter 3 introduces a statistical method for classifying legal cases by doctrinal area or subject matter. It proposes using a latent space approach based on case citations as an alternative to the traditional manual coding of cases, reducing subjectivity, arbitrariness, and confirmation bias in the classification process

Being Pragmatic About Forensic Linguistics

This article aims to provide some legal context to the Authorship Attribution Workshop (“conference”). In particular, I want to offer some pragmatic observations on what courts will likely demand of forensic linguistics experts and tentatively suggest what the field should aspire to in both the short and long run

Law, Statistics, and the Reference Class Problem

Statistical data are powerful, if not crucial, pieces of evidence in the courtroom. Whether one is trying to demonstrate the rarity of a DNA profile, estimate the value of damaged property, or determine the likelihood that a criminal defendant will recidivate, statistics often have an important role to play. Statistics, however, raise a number of serious challenges for the legal system, including concerns that they are difficult to understand, are given too much deference from juries, or are easily manipulated by the parties\u27 experts. In this preview piece, I address one of these challenges, known as the reference class problem, and sketch a solution that I develop at greater length in my forthcoming Essay

A Practical Solution to the Reference Class Problem

The reference class problem is a serious challenge to the use of statistical evidence that arguably arises every day in wide variety of cases, including toxic torts, property valuation, and even drug smuggling. At its core, it observes that statistical inferences depend critically on how people, events, or things are classified. As there is (purportedly) no principle for privileging certain categories over others, statistics become manipulable, undermining the very objectivity and certainty that make statistical evidence valuable and attractive to legal actors. In this paper, I propose a practical solution to the reference class problem by drawing on model selection theory in statistics. The solution has potentially wide-ranging and significant implications for statistics in the law. Not only does it remove another barrier to the use of statistics in legal decisionmaking, but it also suggests a concrete framework by which litigants can present, evaluate, and contest statistical evidence