New Perspectives: A lawyer’s view of statistical experts

Lawyer view of statistical experts“…Experts serve a very important role in legal proceedings, one that is often indispensable.”

A lawyer’s view of the statistical expert‘ was written by Steven L. Willborn, Dean and Schmoker Professor of Law at the University of Nebraska.

The article first explores the dual roles of statistical expert witnesses in litigation, first in an advisory role to the lawyer, and (often) then as a testifying expert. Statistical experts often aid lawyers in evaluating allegations and preparing a case before lawsuits are filed.  He notes that alternative dispute resolution involving arbitration and mediation also rely on statistical evidence.

Although it is an obvious point, Willborn mentions the important fact that expert witnesses are necessarily associated with one of the parties in the case. This obviously has consequences, impacting the statistician who is presented with the particular point of view of the attorney.

Some attention is given to the data and documents utilized by statistical experts in a case, and the role of the expert as providing an opinion, assuming the information provided to the statistician is true and accurate. Willborn notes that experts provide generally concise, pointed testimony, avoiding long, expansive explanations.

Willborn then discusses the distinction between expert and lay witnesses. US rules of evidence make a clear distinction between the two types of witnesses, with the expert witness possessing scientific, technical or specialized knowledge, basing analysis on reliable methodology and assumptions. Non-expert witnesses can testify on a very limited range of topics, and they have no specialized training that qualifies them as an expert in a field relevant to the case. Because lay-witnesses are barred from testifying about matters that require special knowledge, an attorney must take seriously the task of selecting an expert witness.

There is some ambiguity about these designations if they are viewed as a spectrum, with contested identities in the middle. The article discusses an example in which an assistant medical examiner was asked to testify about the facts of the autopsy as a law-witness, and as an expert witness regarding the cause of death.

The relationship between lawyers and statistical experts, which the author refers to as a ‘dance’, is explored next, with Willborn offering the somewhat controversial view that “lawyers, as a general matter, are not primarily interested in scientific integrity or ‘truth’.” He clarifies that an attorney’s first obligation is to protecting the interests of his or her client. Because lawyers are free to retain any expert witness they choose, experts with views that match the lawyer’s view of the case are likely hired. This leads to what WIllborn calls the ‘battle of the experts,’ with two witnesses providing testimony with opposite views.

Willborn explores ethical issues that can arise with the use of expert statistical advice and testimony, including the expert witness fee appearing to be the testimony and opinions of the expert being ‘purchased’ by the lawyer. Potential evidence can also be an ethical consideration, with an expert witness producing multiple drafts of a report, which must be disclosed to the other side.

Finally, the article discusses tensions between the law and statistical evidence. For example, the two different disciplines of the law and statistics would engage with employment discrimination differently. The statistical expert is able to calculate the likelihood that termination rates would occur by chance (and account for variables), whereas the court’s job is more black and white – yes or no, was there discrimination?

Willborn concludes with a quote W. L. Foster, who wrote about the role of expert witnesses almost 120 years ago, “The [expert] witness should come into court with clean hands and a pure heart; with sincerity of purpose; with a tendency and desire to ascertain and recognize truth wherever it may be found; to conceal nothing; mindful of his oath, which requires him to speak not only the truth, but the whole truth.”

This article explores the relationship between statistical experts and attorneys. While the article provides useful and easy to understand information, the context is unusual. Willborn writes from the perspective that the practices and culture of litigation and science are quite different, which he says can lead to statisticians being ‘surprised and confused’ when first involved in litigation. The article’s abstract focuses on Willborn’s idea that statisticians are “almost certain to be uncomfortable” at first. This is not only an unsupported claim, but a strange focus for the abstract since it is not a dominant theme in the article.

J.R. Randall

J.R. Randall is an economist who resides in the Bay Area. He focuses his interest on range of economic topics. He has interest in deep sea fishing and art.