Statutory interpretation methodology is a strange animal because courts do not give it precedential effect. Lower courts (usually) are not bound to follow the methods of higher courts the way they are bound to follow the results, and, to my knowledge, the Supreme Court has never applied the stare decisis theory of Planned Parenthood v. Casey to statutory interpretation methodology.
The recent case of Bond v. United States is a good example of the Supreme Court not giving statutory interpretation methodology precedential effect. There the Court interpreted the term “toxic chemical” in the Chemical Weapons Convention Implementation Act of 1998 in a way that explicitly contradicted its statutorily-defined meaning. It did so to avoid overriding “the usual constitutional balance of federal and state powers.” True, the Court commonly uses this so-called federalism canon to construe ambiguous statutes to avoid intruding on traditional state functions. But, as Justice Scalia pointed out in his concurrence, the Court has never used this canon to show that a statute is ambiguous in the first place. Chief Justice Roberts essentially confessed to doing this: “In this case, the ambiguity derives from the improbably broad reach of the key statutory definition [of] the term—‘chemical weapon.’” In other words, the Court has created a new method for interpreting statutes: the intrusion on traditional state functions can render an otherwise clear statute ambiguous.
Perhaps the creation of a new rule of statutory interpretation, by itself, is insufficient to warrant stare decisis analysis. However, in Bond, the Court did not simply create a new method for interpreting statutes. It adopted a new rule and displaced an old one. As Justice Scalia pointed out, the old rule had said: “When a statute includes an explicit definition, we must follow that definition, even if it varies from that term’s ordinary meaning.” Had the Court applied that rule, it would have followed the Act’s own unambiguous definition of “chemical weapon.” Thus, the new “an intrusion on state power makes an otherwise clear statute ambiguous” rule displaced the old “follow the statutorily-defined meaning” rule.
This is a problem because lawyers rely heavily on analytical procedures and rules of interpretation that have evolved over a thousand years of the Anglo-American legal tradition. Suppose a new case comes up that poses a question similar to the one in Bond. Can the parties be confident that courts will apply the Bond rule? Not necessarily. Because statutory interpretation methodology (usually) is not binding, Bond does not actually invalidate the older “follow the statutorily-defined meaning” rule, even in the cases that involve a clash between state and federal power. This gives courts a choice between applying the new rule and the old one. This means that it is virtually impossible to know what a court will construe the statute to mean, and virtually impossible to know what one has to do in order to comply with it.
The problem gets worse, for there is also the void-for-vagueness doctrine to consider. The gist of the void-for-vagueness doctrine is that if a statute provides no guidelines that help a person know what is and is not allowed, then it violates due process to prosecute the person for violating it. Justice Scalia warned in his opinion that the Court’s rewriting of the statute left it unclear what exactly a “chemical weapon” is, thus raising vagueness problems. But a similar problem arises when a person cannot predict how a court will decide what a law means. While the vagueness doctrine is normally applied to the statutes themselves, it also should apply to the techniques courts use to decide on legal definitions. After all, we know from Marbury v. Madison that the judiciary gets to say what the law is. And people will presumably do what is necessary to comply with a statute as the courts will interpret it.
If there is no stare decisis for statutory interpretation methodology, courts will devise different, perhaps conflicting, methods of interpretation. Since ordinary people have no way of knowing which interpretation the courts will choose, the statute provides them with no standard of conduct, even when statutory language is unambiguous. Even where a law contains clear definitions, a person cannot know whether courts will follow the plain language, or devise a “narrowing construction” instead.
To avoid this serious constitutional issue, perhaps the Court should clean up its statutory interpretation methodology by creating a hierarchy of interpretive canons so that people will be able to predict how courts will interpret statutes. And it should stop issuing opinions like Bond, which makes this task all the more difficult.
Stephen Stich is a law student at Yale University and a summer clerk at the Pacific Legal Foundation.