Judge Kavanaugh will undoubtedly be interrogated about his views on overturning Supreme Court decisions (the law of precedent or stare decisis, as it’s called in Latin) during his confirmation hearings next week, but there is ironically little that Kavanaugh has written on the subject.

Unlike other judges who have been academics and written on precedent, Kavanaugh has not been a full-time professor.

As a lower federal court judge, Kavanaugh has had no experience in applying the Court’s doctrine of precedent, because the Supreme Court has strongly warned lower court judges that they cannot overturn the Supreme Court’s precedent, and Kavanaugh has strictly followed that instruction.

Kavanaugh is the co-author of a 2016 book on The Law of Judicial Precedent.  But he was one of 12 co-authors, and all contributed to the book “as one voice” and did not sign any particular section of the book.  So nothing can be attributed to Kavanaugh or any other co-author.

So, there’s not much in Kavanaugh’s writings.

That doctrine is muddled, and scholars tend to characterize judges, in the most general terms, as having a “strong” or “weak” view of whether precedent controls. Imagine plotting the current group of 8 justices on a spectrum.  Breyer might have the “strongest” view of precedent on constitutional issues, while Thomas might have the “weakest.”

The Supreme Court’s Justices have overturned their own decisions more than 230   times in the past two centuries. In recent decades, the Justices have developed a multi-factor test for deciding when to overrule prior decisions.  And the Court recently applied that multi-factor test in two decisions in June.

Those six factors are:  whether the original decision is settled, wrongly decided, and workable; whether factual changes or legal changes have eroded the original decision; and whether reliance interests in the original decision are substantial.

Each of these factors contains considerable wiggle room.

But the six factors answer three questions: Did the Court err?  How big was the error?  What’s the cost of correcting the error?

On June 21, in South Dakota v. Wayfair, the “e-commerce tax” case, retiring Justice Anthony Kennedy wrote the majority opinion for five justices and overturned two prior decisions, applying some but not all of the factors.  Chief Justice Roberts dissented from overruling the prior cases.

Contrast Wayfair with Janus v. AFSCME, the public sector union fees case, decided a week later. In Janus, Justice Samuel Alito wrote the majority decision for five justices, including Chief Justice Roberts, and overruled the Court’s 1977 decision in Abood v. Detroit Board of Education.

From time to time, some Justices have suggested another factor: precedent shouldn’t be overturned without “special justification.”

This vague, seventh factor is typically cited by those resisting overruling and rarely if ever by those supporting overruling.  It seems more a cliché than a useful element of legal reasoning.

If it seems that the doctrine is in need of clarification, many scholars would agree. The Court could start by throwing out the “special justification” factor.  The multi-factor test is the justification.  A vague, seventh factor isn’t needed.

Expect to see Kavanaugh address the subject in a general—dare say–“academic” way, without taking a specific position.