Modern lawsuits are expected to resolve enormously complex scientific issues. Yet the courts have little independent expertise of their own. Instead they rely on the testimony of expert witnesses called by the litigants. As Manhattan Institute Senior Fellow Peter Huber points out in his forthcoming book, (Liability: The Legal Revolution and Its Consequences) the provision of expert witnesses has become a booming industry. "Today one referral service in Pennsylvania maintains a nationwide list of about 10,000 experts grouped in 4,000 categories, and reports a 15 percent annual growth in its listings. Classified ads in the back pages of legal journals offer counsel on bicycle mishaps, grain dust blasts, playground traumas, battery or bottle explosions, hotair balloon accidents, radiation incidents, and accidents involving lawn mowers, toys, and beer barrels."
"The current system of litigation," declares Professor E. Donald Elliott of the Yale Law School, â€œcreates strong incentives for lawyers to select experts with views outside the mainstream of scientific opinion." Unfortunately, juries cannot always distinguish good from bad science in brief presentations, and experts with extreme, eccentric, or downright unsound viewpoints can make articulate and personable witnesses. Addressing the Yale Law School's conference on civil procedure in April (whose panel on discovery abuse was summarized in Civil Justice Memo #9), Elliott said practitioners of what he termed "marginal science," scholars whose views are sharply at odds with those of the medical mainstream, have dramatically changed the balance in toxic tort litigation in recent years. One circle of professional witnesses, who refer to themselves as â€œclinical ecologists," claim that even minuscule amounts of a wide variety of chemicals can weaken the body's immune system. They thereby attribute to toxic exposure the potential for causing almost every malady known to mankind, including infectious disease, anxiety, and depression. The scientific establishment has in general taken a different view, he said; in fact, the American Academy of Allergy and Immunology has issued a statement strongly repudiating the methods and results of the clinical ecology school. Yet bidding for these witnesses remains intense: one active witness is said to charge $20,000 per plaintiff.
Matters are unlikely to improve so long as lawyers have reason to choose the most extreme witness in their favor that a jury is likely to believe. But the remedy is not obvious either. Who should separate the false witnesses from the genuineâ€”given that entirely legitimate viewpoints may be out of style at any one moment?
Disallowing Testimony, Or Putting It in Perspective
Until recent times, courts actively sought to identify and exclude substandard scientific testimony. Under the old "Frye rule," which dates back to 1923, expert testimony could not be introduced unless it was based on principles that "have gained general acceptance in the particular field." The Frye rule became harder to implement as issues grew more complex and the scientific community fragmented into sub-communities. Whether a view has "gained general acceptance in the particular field" depends on how the "field" is defined. A group of offbeat thinkers may put out their own journal and even run a university department here or there. In any event, Frye lapsed into disuse after a 1975 shift in the Federal Rules of Evidence that encouraged the admission of expert testimony whenever it might be helpful to a jury.
An alternative way for courts to regulate expert testimony would be to help the jury place it in better perspective. They could pursue such an "information enhancement" strategy in at least three ways. First, courts could appoint their own experts to testify on the issues at stake. Judges are in general reluctant to exercise this option, whether from fear that the court-appointed outsiders they select will be attacked as biased or less than fully expert, or because they do not want to assume a power that could be decisive in influencing the jury.
A second method would be for the court to appoint not a single expert but a panel of experts reflecting a range of scientific opinion. Yet this technique too is rarely used. Accurately sampling the spectrum of scientific thought is no easier (and may be harder) than finding a single qualified expert. Unless such a panel conferred and deliberated in public before reaching its consensus, the parties to the suit could charge it with unfairness. Yet public deliberations may be less than frank. Then there are the sheer logistical problems. Panel members might have to stay on call while court deliberations dragged on for months and new issues emerged. Who would pay? And is this the best use of top scientists' time?
Another approach, perhaps less costly than convening a long series of ad hoc panels to address the specifies of each case, would be to develop standing panels to assess generic issues that come up in cases again and again. In fact. some courts are experimenting with such "hybridâ€ judicial/administrative institutions. But the verdict on these innovations is still out. Courts have traditionally been averse to assuming executive powers, the panels they rely on may be swayed by factors other than "good science," and there is many a slip between the generic scientific question and the specific case.
Toward Incentive-Based Procedure
Elliott concluded by proposing a variation on the Frye rule: expert witnesses would be obliged to introduce the scientific bases for their evidence in written form, before its submission in open court. If an opponent managed to cast substantial doubt in the judge's mind on the scientific validity of the evidence, the judge could appoint an independent expert who would inform the jury "whether the principles, techniques and conclusions by the experts for the parties would be generally accepted as valid by persons learned in the field." The idea is to give lawyers incentives to hire experts whose views, though favorable to their case, were not so eccentric as to risk embarrassment in peer review.
Peter Huber, commenting on Elliott's paper, observed that the cultures of science and law are hard to mix. In science the painstaking and thorough gathering and interpretation of evidence is the end in itself. In legal advocacy, witnesses and evidence are "a bothersome and often inconvenient necessityâ€”an instrument to be used for other purposes." Scientists work on the honor system, and are aghast to discover knowing deception. Good trial lawyers expect the worst from their opponents, and are seldom disappointed. In science, no issue is ever truly settled; in law, closing the case, for better or worse, is all-important.
Of the three approaches that Elliott outlines, Huber said, the first, selective exclusion of evidence, works well if the judge understands something of the science at the outset. Unfortunately, "most judges aren't either strong-willed or confident when the issue at hand is whether one part per billion of trichloroethylene in the drinking water increases the rate of birth defects." The second routeâ€”promoting "good" evidence, usually by appointing neutral experts to evaluate testimonyâ€”leaves the court roaming the streets like Diogenes looking for the perfectly honest and objective scientist, a task that, when feasible at all, cannot be reduced to a routine, as the procedures of a standardized court system demand.
Elliott's proposal, Huber said, would seem to combine the first two. It invokes outside expertise, not to establish a positive account of what happened, but to impeach dubious assertions by other experts. Its most significant element, Huber said, is its call for studies to be filed in formal writing well ahead of time. Where the culture of law stresses the examination of eyewitnesses in person, the culture of science stresses the use of written works of scholarship that peers can review at a more deliberate pace. Face-to-face lawyer-led questioning may work in exposing bald-faced lies, but it is much less effective in revealing the omissions and incompleteness that are the real failings of most bad expert testimony.
In the general discussion that followed, Federal District Court Judge Jack Weinstein observed that juries often find it useful to give shaky testimony the benefit of the doubt in order to compensate sympathetic and badly hurt plaintiffs. If so, Huber responded, the law is in deep trouble. When it allows other objectives to override the search for truth, it tends to bring itself into disrepute.