Steven Calabresi and I have a Friday Wall Street Journal op-ed advocating 18 year term limits for Supreme Court Justices, which anticipates the Duke conference on ours and other such proposals that will be held on Saturday.

Our op-ed is now online at OpinionJournal.com (quick, free registration required).

The draft of our manuscript can be downloaded from our page at SSRN, where it is posted along with an abstract.

Here is an excerpt from the op-ed in Friday's Wall Street Journal:

SUPREME GERONTOCRACY

The case for reasonable term limits on the Supreme Court.

It has been almost 11 years since the last vacancy opened up on the U.S. Supreme Court. The current group of justices has served together for longer than any other group of nine justices in American history. What is more, the average tenure of justices has gotten a lot longer in the last 35 years. From 1789 until 1970, justices served an average of 14.9 years. Those who have stepped down since 1970, however, have served an average of 25.6 years. This means justices are now staying more than 10 years longer on average on the Supreme Court than they have done over the whole of American history.

The reason for this is not hard to find. Recently, the average age at time of appointment to the Court has been 53, which is the same as the average age of appointment over the rest of American history. The retirement age, however, has jumped from an average of 68 pre-1970 to 79 for justices retiring post-1970. Two of the current justices are in their 80s, two in their 70s, and four more between 65 and 69. Only one, Clarence Thomas, is younger than 65. The current Court is nothing less than a gerontocracy—like the leadership cadre of the Chinese Communist Party.

Indeed, David Garrow's scholarship has shown that decrepitude has been a problem with the last 10 justices to retire, those who left the bench from 1971-94. By some accounts, half of the last 10 retirees have been too feeble or mentally incompetent to participate fully in deliberating and deciding cases—or even in some instances, to stay awake during the few mornings of oral arguments. While mental incompetence was rare in the first century on the Court, since 1898 it has become a regular occurrence for justices who serve more than 18 years; by one estimate about a third were mentally incompetent to serve before they finally retired.

UPDATE (Sunday): I edited this post to add a link for the free, online version.