“What is Judicial Ideology, and How Should We Measure it?”

Corey Yung

Corey Rayburn Yung is a Professor at the University of Kansas School of Law. His scholarship primarily focuses on sexual violence, substantive criminal law, and judicial decision-making. Yung’s academic writings have been cited by state and federal courts, including the Supreme Court of the United States. Before Yung began his professorial career, he served as an associate for Shearman & Sterling in New York and clerked for the Honorable Michael J. Melloy of the United States Court of Appeals for the Eighth Circuit.

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5 Responses

  1. A.J. Sutter says:

    What about other forms of ideology, such as a judge who uses law & economics-based reasoning? There are both liberal and conservative judges who fall into that pot.

  2. Corey Yung says:

    Hi A.J.,

    I will talk about the unidimensionality in a future post as it is an important point. Certain methods lend themselves to multidimensional measurements better than others. One difficulty, though, is while most people have a pretty good idea of what “liberal” and “conservative” mean, other dimensions are more difficult to nail down. A unidimensional spectrum also can capture the other dimensions to the degree that they intersect conservative and liberal thought. For example, in my measure, Judge Easterbrook shows up as very conservative. In contrast, Judge Posner shows up as a moderate leaning toward slightly liberal. On a unidimensional spectrum, that probably makes sense. Judge Easterbrook’s law and economics approach will tend to lead him to agree with conservatives more. In contrast, Judge Posner’s pragmatism would tend to make him a moderate as it might point in either direction in a particular case. Nuance is lost with unidimensionality, but the results still allow for more sophisticated interpretation. It also should be noted that at least for the United States Supreme Court, prior research has shown that the unidimensional political spectrum covers a large majority of the ideology of the Justices. That shouldn’t be terribly surprising as judges are nominated by a President from one of two parties and confirmed by a Senate that is essentially composed of two parties. And judges are drawn from a society that largely structures itself around two parties. That most ideologies of judges can be mapped on a unidimensional spectrum would be the expected result.


  3. Bryan Gividen says:


    I am assuming your working paper covers the same issues you will bring up in your next post. After reading through it, I was still skeptical of using the district judge’s political disposition as a measuring stick for going in or outside of party lines, primarily in unanimous cases. Those situations seem to be a clear legal question as opposed to an ideology question. (Using the baseball analogy, a down the middle strike would be a 9-0 opinion while a 5-4 split would be an inside corner near the knees – more about the individual umpire and less about “rules.”) Would you be able to cover that in a response or in one of your subsequent posts?

  4. A.J. Sutter says:

    Thanks for your reply. I’d meant to use scare quotes, à la “liberal” and “conservative”, to reflect the purely conventional nature of those labels. Even the identification of those labels with the political parties is shaky, because of the same unidimensionality you mention.

  5. Corey Yung says:

    Hi Bryan,

    I will be covering the issue you raise in a future post. It is definitely a tricky issue. However, given that 98.4% of the cases in my dataset are unanimous opinions, I think it is a stretch to say that all or even a substantial majority of those are “easy” cases. The high rate of agreement might be largely due to panel effects, strategic incentives, or norms of consensus. My measure attempts to properly weight the various instances of disagreement among panelists and with the district judges so that the 3-0 affirmances do not have the same significance as 2-1 reversals (particularly in criminal cases with a deferentail standard of review).