In my last blog, I noted the problem of selection bias in studying appellate court decisions and also pointed out that Harold Spaeth is coding a sample of denied certiorari petitions that will help us assess the degree to which this problem exists at the SCOTUS. In a recent email from him, he let me know that the Burger Court sample is completed (available at the South Carolina JURI site), and that:
“I am not quite finished coding Blackmun’s docket sheets on the Rehnquist Court (1986-94), but I expect to finish this database by early Fall. It will contain a sample of the Court’s denied petitions allowing individuals to ascertain the proportion of petitions dealing with various legal and constitutional provisions that the Court accepted. No longer will any basis exist for selecting on the dependent variable. The direction of the denied petitions is also provided along with other more or less pertinent data.”
Thanks to Harold for this information.
Of course, this does not solve the problem of selection bias at the U.S. Courts of Appeals or even the trial courts, since the concern could be expressed that disputes settle and therefore there is selection bias in any study of judicial decision making.
This problem ultimately cannot be resolved completely because, as I said in my last post, at some point, it becomes turtles all the way down. Of course, the extent to which selection bias matters depends on the questions the researcher is asking. If you are using court cases as your database to say something about disputes writ large, you’ve got a problem. But if you are studying court cases to say something about court cases, well, then I’m less concerned, even in appellate courts–assuming they have mandatory dockets. The problem obviously becomes more pronounced when courts exercise discretion over their own dockets.
In my next blog, I’ll have something more to say abuot alleged inaccuracies or miscodings in the Spaeth or Songer Databases.
