Expert Witness Mining – Antic Proposals for Reform

Law Reviews and Altered States of Reality

In 2008, Justice Breyer observed wryly that “there is evidence that law review articles have left terra firma to soar into outer space”; and Judge Posner has criticized law review articles for the “silly titles, the many opaque passages, the antic proposals, the rude polemics, [and] the myriad pretentious citations.” In 2010, Justice Scalia, who was a law-review-producing law professor for the University of Virginia for several years, responded to a lawyer’s oral argument, in McDonald v. City of Chicago, by suggesting that the argument had no support in Supreme Court precedent, but the unsupported argument would make the lawyer the “the darling of the professoriate.” At the June 2011 Fourth Circuit Judicial Conference, Chief Justice Roberts opined that law reviews are generally not “particularly helpful for practitioners and judges.”  In his words:

“Pick up a copy of any law review that you see and the first article is likely to be, you know, the influence of Immanuel Kant on evidentiary approaches in 18th-century Bulgaria, or something, which I’m sure was of great interest to the academic that wrote it, but isn’t of much help to the bar.”

See Debra Cassens Weiss, “Law Prof Responds After Chief Justice Roberts Disses Legal ScholarshipAm. Bar Ass’n J. (July 07, 2011). Lawyers would think the Justices view law review scholarship as a useless but generally harmless activity. Sometimes, however, law review articles can actually be harmful.

Selection Effects in the Retention and Presentation of Expert Witnesses

The complaints about law review scholarship are obviously based upon extremes and travesties. Interestingly, Judge Posner himself has been no slacker when it comes to producing law review articles with “antic proposals.” See, e.g., Richard A. Posner, “An Economic Approach to the Law of Evidence,” 51 Stan. L. Rev. 1477, 1541–42 (1999). In the tradition of non-traditional, rationalist proposals that ignore experience and make up something completely untested, Judge Richard Posner has advocated rule changes that would require lawyers

“to disclose the name of all the experts whom they approached as possible witnesses before settling on the one testifying. This would alert the jury to the problem of ‘witness shopping’.”

Posner, 51 Stan. L. Rev. at 1541. The point of Judge Posner’s radical reform is to alert triers of fact to whether the expert witness testifying is the first, or the umpteenth expert witness interviewed before a suitable opinion had been “procured,” so that the fact finder can draw the“ reasonable inference” that the case must be weaker than presented if the party went through so many expert witnesses before coming up with one who would testify in the case. If one party disclosed but one expert witness, the one that actually testified, and the other party disclosed X such witnesses (where X >1), then the fact finder could find in favor of the first party upon the basis of the so-called reasonable inference.

Posner’s proposal is at best a proxy for accuracy and validity in expert witness opinion testimony, and one for which Posner presents no evidence to support his hoped-for improvement in juridical accuracy. Not only does Judge Posner present no evidence that his proposed reform and suggested inference would be in the least bit reasonable and probative of the truth, he fails to address the obvious incentives that would be created by his proposal. Fearing the prejudicial inference from having consulted with “too many” expert witnesses, lawyers, operating under the Posner Rule, would have strong incentives to go to the expert witness “one-stop-shopping” mall, where they know they can obtain expert witnesses guaranteed to align themselves with the needed litigation positions and claims. The Posner Rule would also give a strong advantage to lawyers more skilled in vetting and selecting expert witnesses, to the detriment of less experienced lawyers. Of course, lawyers who are willing to go shopping at the meretricious mall or to employ a “cleaner” who brokers the selection without footprints might escape the bite of the Posner adverse inference.

Posner’s proposed rule ignores what is at the heart of identifying and selecting expert witnesses to testify. Obviously lawyers must identify potential witnesses with suitable expertise to address the issues raised by the litigation. Database searches, such as PubMed and Google Scholar searches for bio-medical experts, can go a long way towards identifying candidates, but interviews are important as well. Posner would chill lawyers’ effective representation by placing an adverse inference upon their diligence in any contact with the person other than the “one” who will be anointed to be the party’s designated testifier.

Meetings and interviews with prospective expert witnesses to ascertain whether the witness candidate has sufficient time and interest in fulfill the litigation assignment. Expertise in the area is hardly a guarantee that the candidate will be interested in answering the specific questions that are contested in the litigation. The lawyers must also ascertain whether the witness candidate has the stamina, patience, and aptitude for the litigation context. Not all real experts do, and the consequences of engaging an expert who does not have the qualities to make a good expert witness can be disastrous. Witness candidates must also be screened for their communication skills, their appearance, and even basic hygiene. The most brilliant expert who mumbles, or who is unkempt, is useless in litigation.

Lawyers must evaluate witness candidates for conflicts of interest, many of which are unknowable until there is a face-to-face meeting. Does the witness candidate have a significant other or child who works for the litigation industry (plaintiffs’ bar) or for the defendant industry under assault in the litigation at hand? Either way, the candidate may be compromised. Was the candidate mentored by an expert witness on the other side? Is the candidate on an editorial board with the adversary’s witnesses? Is the candidate close personal friends of the adversaries or their witnesses, such that he will be less than enthusiastic in showing the infirmities of the other side’s positions? Any of these questions could lead to answers that practically disqualify a witness candidate from consideration. Proceeding without such vetting could be catastrophic for the client and counsel. Burdening the vetting process with the threat of an adverse inference is deeply unfair to diligent counsel trying to represent and serve their clients.

And there are yet additional considerations that require exploration with any witness candidate. Expert witnesses are not equally able to deal with adverse authority in the form of a noted scientist who has taken a stand on the litigation issue, or a superficially appearing authoritative author who has published an adverse opinion. As well trained as they might be, some real experts are “sheep,” who are most comfortable following the herd, and not independent thinkers. Not all experts are willing or able to read studies as critically as needed for the litigation situation, which can sometimes be more demanding than the scientific arena. Lawyers charged with retaining expert witnesses must assess their clients’ positions and determine how well their expert witnesses will perform under all the circumstances of the case.

Professor Christopher Robertson proposes an even more radical reform of the law of expert witness by removing the selection and control of expert witnesses from parties and their counsel, completely. Robertson would somehow create a pool of expert witnesses on the issues in each case, and assign them to parties in a double-blinded randomized fashion. Christopher Tarver Robertson, “Blind Expertise,” 85 N.Y. Univ. L. Rev. 174, 211 (2010). Aside from depriving litigants of autonomy and control over their cases, this approach has even greater potential for generating false results. How do the expert witness come to be retained for this process? Any two expert witnesses may very well come to an incorrect analysis precisely because they do not have the benefit of each other’s report to develop the full range of data to be considered. What if the expert assigned to plaintiff concludes that there is no case, but the expert assigned to the defendant concludes that the plaintiff’s case is meritorious? Normally, plaintiffs’ expert witnesses must file their reports in advance of the defense witnesses, who then have the opportunity to rebut but also the benefit of all the data included. Simultaneous reports risk major omissions of data to be considered on both sides. The adversarial cauldron works to ensure completeness in what data and studies are considered.

Now comes Jonah Gelbach to attempt a probabilistic, theoretical defense of reforms in the Posner-Robertson mold. Jonah B. Gelbach, “Expert Mining and Required Disclosure,” 81 U. Chicago L. Rev. 131 (2014). Professor Gelbach is a well-trained economist, and a recently minted lawyer (Yale 2013), who is now an Associate Professor at the University of Pennsylvania Law School. Gelbach’s experience with the practice of law is limited to working as a law-school intern at David Rosen & Associates, in New Haven, Connecticut, before joining the Penn faculty. His proposals may need to be taken with a 100 grains of aspirin.

Although Gelbach disagrees with particulars of the Posner-Robertson proposals, Gelbach joins with them to opine that “[t]o the extent that additional fully disclosed expert testimony increases the fact finder’s information, we can expect a beneficial increase in accuracy.” Gelbach at 133. Gelbach’s dictum, however, is an ipse dixit, and he offers only a limited hypothetical case in which full disclosure of data should be required to solve the problem. And even in his hypothetical case, the disclosure of the identities of the testers is unnecessary to correct the error that Gelbach predicts. Gelbach’s call for the disclosure of consulting expert witnesses introduces only a collateral issue that has nothing to do with the accuracy of the scientific reasoning.

Gelbach analogizes “witness shopping” to data dredging and multiple testing, with a known inflation in the rate of false positive outcomes. If a party directs multiple to conduct single outcome measurements or tests, then that party can recreate the results of multiple testing without having to disclosure the number of independent tests. Gelbach’s argument is at its strongest for a simplistic model of a simple measurement, with errors normally distributed, with accuracy of the measurement tied to the outcome of the case. Gelbach at 136. Gelbach analogizes expert witness mining with data mining, and goes so far as to provide a calculation of false positive rates from multiple testing.

The sort of multiple testing Gelbach condemns is even more obvious when something other than random error is involved. Consider the need of litigants to have chest radiograph interpreted for the presence or absence of a pneumoconiosis in occupational dust disease litigation. Not only is there an intra-observer variability, there are potential or known subjective biases in radiograph interpretations. Gelbach need not worry about multiple testing because the need for economic efficiency already encourages many lawyers to employ radiologists who are must biased in favor of their clients’ positions. The bigger problem would be to encourage lawyers to obtain an honest second opinion, which might make them less strident about their litigation positions when discussing possible settlement.

Gelbach appears to believe that mandatory disclosure of the number of expert witnesses hired as well as the contents of the written and oral reports issued by the party’s nontestifying expert witnesses is needed to abate the potential harm from “expert mining.” By introducing the probabilistic modeling of Type I and Type II errors, however, Gelbach elevates proofiness over clear thinking about the issue. The simple solution to Gelbach’s soil measurement hypothetical is to require disclosure of all testing data, regardless whether conducted by expert witnesses designated as testifying or as consulting. All are agents of the party for purposes of creating data in the form of the hypothesized soil measurement. Indeed, Gelbach’s hypothetical envisions a technical laboratory that conducts such measurements, and the lab might not even be associated with a person designated to serve as an expert witness on the litigation issues.

Gelbach’s soil-measurement case is thus, for the most part, a straw-person case. In the vast majority of cases, multiple expert witness interviews leading up to selection and retention is, however, not at all like multiple testing, either in its ability to generate deliberate false positive or false negative opinions. The evidence remains what it is, and the parameter unchanged, whatever the qualitative judgments of the witness candidates. In most litigation contexts, the data upon which the expert witnesses will rely comes from published studies, and not from a single measurement under either side’s control and ability to resample many times through the agency of multiple expert witnesses. The Rules need to help the triers of fact discern the truth, not irrelevant proxies for the truth. If the triers of fact are incompetent to adjudge the actual evidence, then we may need to find triers who are competent.

The extension of the soil hypothetical to all of expert witness opinion testimony is unwarranted. Accuracy and validity of expert opinion is not “independent and identically distributed.” Truth and accuracy in scientific judgment as applied to litigation scientific questions are not random variables with known distributions.

A party may have to comb through dozens of potential expert witnesses before arriving at an expert witness with an appropriate, accurate answer to the litigation issue. When confronted with a pamphlet entitled “100 Authors against Einstein,” Albert Einstein quipped “if I were wrong, one would have been enough.”  See Remigio Russo, 18 Mathematical Problems in Elasticity 125 (1996) (quoting Einstein). Legal counsel should not have their clients’ cause compromised because they had the misfortune of consulting the “100 Authors” before arriving at Einstein’s door. The Posner-Robertson-Gelbach proposals all suffer the same flaw: they defer unduly to conformism and ignore the truth, validity, and accuracy of procured opinions.

Disputes in science are resolved with data, from high-quality, reproducible experimental or observational studies, not with appeals to the number of speakers. The number of expert witness candidates who were interviewed or who offered preliminary opinions is irrelevant to the task assigned to the finder of fact in a case involving scientific evidence. The final, proffered opinion of the testifying expert witness is only as good as the evidence and analysis upon which it rests, which under the current rules, should be fully disclosed.