Don't Rely Too Much on Common Sense:

The Tenth Circuit just reversed the insider trading conviction of Joseph Nacchio, former CEO of Qwest. (Congratulations to my Mayer Brown colleague Andy Schapiro, who cofiled an amicus brief on behalf of the National Association of Criminal Defense Lawyers supporting reversal.)

The reversal stemmed from the trial judge's exclusion of economic expert evidence. Among other things, the trial judge concluded that the evidence would "invit[e] the jurors to abandon their own common sense and common experience and succumb to this expert's credential." The panel majority responded:

While economic analysis sometimes asks jurors to "abandon their own common sense," App. 3920, that is not a reason to deem expert testimony inadmissible. Armchair economics is not the way to decide complex securities cases.

Absolutely right.

It is interesting that the appeal to authority is a well known logical fallacy, but that authoritative testimony is required in complex cases, like medical malpractice cases. Obviously, there is a conflict between providing the jury with sufficient explanation to allow them to properly consider the evidence, and allowing the credentials of the witness to be the evidence. Judge Nottingham's trying to avoid this conflict by trying to avoid the evidence, particularly when such might bear on the guilt of a criminal defendant, strikes one as odd.

In general, it is probably not a good idea to assume that jurors are too stupid or gullible to serve on juries.
3.17.2008 7:46pm
EH (mail):
z9z99: I believe you're mixing the apples and oranges of homonyms. An appeal to authority may be a logical fallacy, but being an authority isn't.
3.17.2008 7:51pm
Appeal to authority as a fallacy doesn't mean what most people think it means.

In short form, there's two basic forms -- there's appeal to false authority and standard appeal to authority. A false authority is someone who isn't actually an authority in a relevent area, or whose authority is disputed. (Think, say, engineers discussing evolution or a cult-leader discussing Christianity).

In those cases, you don't actually HAVE an authority or it's a field in which, for one reason or another (too subjective, for instance) no authority is really possible.

In regular appeal to authority, it's only a fallacy if you assume the authority is infallible.
3.17.2008 7:53pm
Didn't Nacchio also claim in his original trial that Qwest was going to benefit from some large gov't contracts, which were based on gov't wiretaps, that never came to pass?
3.17.2008 7:54pm
K Parker (mail):
In regular appeal to authority, it's only a fallacy if you assume the authority is infallible.

Or, if you state the existence of the authority as your only argument, rather than introducing what the authority says.
3.17.2008 8:07pm
While I appreciate the replies, the appeal to authority is a logical fallacy because the validity of an assertion does not depend on the credibility of its source. Some opinions are more likely than others to comport with fact, and thus it is reasonable to consider them in ascertaining the facts, but the assertion of the world's greatest authority on some matter is not proof.

Of course, most jurors are sophisticated enough not to base their decisions on the credibility of a single source.
3.17.2008 8:12pm
PaulK (mail):
The problem is not that Z9Z99 has mis-stated the fallacy of appeal to authority, but rather that he appears to misunderstand what purpose expert testimony plays in a trial. The expert is not brought in to say (although counsel often attempts to get him to do so) "The Defendant is guilty/liable, and I know this because I am an Expert." Rather, the expert serves to educate the jury as to what the specific standard of care, customary practice, or legal requirement of the given technical field is. An ordinary juror knows that insider trading or medical malpractice is wrong. But the intricacies of the standards that bind doctors and stockbrokers are such that he probably does not know without assistance whether what the defendant did constitutes that crime/tort. It's simply a matter of information, not persuasion or authority, per se.
3.17.2008 8:45pm

I think you have confused me with Judge Nottingham. I am not making any statements about what the role of expert testimony is or should be. I am merely recognizing the very pertinent real-world fact that it is possible that some jurors may be unduly swayed by an expert's credentials. I also stated that this is not (as Judge Nottingham appears to have done to the irritation of the Tenth Circuit) reason to withhold such testimony from the jury. And while I agree that ideally, the role of an expert is to educate the jury, experts are allowed to opine on ultimate issues; consequently, there is a risk (clearly acceptable) that an expert's testimony may be taken not only as persuasive, but as a practical matter, conclusive. This is so, for example, in medical malpractice actions when the expert testifies to the issue of causation. ("The plaintiff would not have had the outcome she did if the physician had prescribed Y instead of X"). Obviously, in most circumstances, there is no way to prove this proposition so the jury must necessarily look to the substance of the opinion, not merely for education, but for its persuasive effect on an ultimate issue. We trust juries to know where to draw the line.

The ambiguity that seems to make this such a fun topic, is that logic is concerned with proof, and testimony is concerned with persuasion. Law is one of the few areas where you are right (even if you are wrong) if and only if you persuade someone else you are right. As a practical matter, arguments that are, strictly speaking, logical fallacies, as practical matters are very persuasive. See the curent presidential campaigns, for example.
3.17.2008 9:44pm
Expert testimony is a two edged sword. I agree that it can be useful. However, juries are not morons (most juries anyway), and shouldn't need an expert to explain to them the basic facts of life.

My very first trial was a medical malpractice case in which my client had gone to the emergency room with a broken jaw; they didn't X-ray or otherwise find out what the problem was and sent him home with painkillers. He nearly lost his jaw as a result. And I nearly lost the case -- as in the judge wasn't going to let it go to the jury -- because it honestly didn't occur to me that anybody over the age of five would need to have an expert explain to them that yes, it is medical malpractice to send someone home with a broken jaw.

I think one of the reasons laypeople often hold the law -- or at least the courts -- in low esteem is because they see common sense take a back seat to formal rules, that in any given case may or may not make sense. A certain amount of that is unavoidable, but not nearly as much as we have.
3.17.2008 10:44pm
Jim Harper (mail) (www):
I think the court was mistaken to ratify the trial court's exclusion of the evidence that Nacchio believed Qwest had money coming from the secret government contracts. More, and the proof that I never practiced law, is here.
3.17.2008 11:21pm