Positive Political Theory and the Study of U.S. Supreme Court Decision Making: Understanding the Sex Discrimination Cases

Published in 1996. New York City Law Review 1 (1): 155-201. (Inaugural issue of the journal.)

Lee Epstein
Thomas G. Walker

Introduction

How do justices of the U.S. Supreme Court reach decisions? To answer this question, social scientists have invoked an increasingly sophisticated set of statistical tools. While in yesteryears simple counts of, say, the number of dissents cast by justices would have suffered, in today’s academic marketplace analytic models that permit the consideration of more than one factor at a time are omnipresent.

That the statistical tool chest of social scientists has expanded substantially over the last half century or so is not at all that surprising.  After all, scholars working in so many of the social sciences—from psychology to sociology to political science - have become adept methodologists.  Almost all graduate programs require their students to take at least one course in statistics—as well they should.  It would be nearly impossible to read the various disciplinary journals without a working knowledge of, at the very least, multiple regression analysis.

And yet, while those of us who study courts—like most other scientists—occasionally invoke the tools of statisticians to conduct our research, we have often looked toward lawyers for our theoretical grounding.  When law schools were advocating positivist (or analytical) jurisprudence, our writings followed suit.  When the legal realists of the 1920s and 1930s rejected positivism for sociological jurisprudence, many social scientists too abandoned analytical approaches and began to develop more “realistic” models of judicial decision making.

Now that a new moment—called positive political theory (PPT)—has emerged from the halls of the nation’s law schools, a natural question emerges: Will social scientists adapt its theoretical premises to their work?  We argue that the answer is yes, for PPT provides a good deal of leverage to answer perennial and central questions concerning U.S. Supreme Court decision making.

We develop this argument in four steps.  In the first step we provide a brief overview of the relationship between political science theories of judicial decision making and those that have been offered by law professors.  Our goal here is to explain how and why social scientists adapted sociological jurisprudence to their research.  In the second step, we turn to the PPT movement.  We explore the central assumption on which PPT accounts of courts rest and argue that PPT will make some inroads into the social science literature if it can help analysts to unravel the complexities of decision making - just as legal realism did.  The third step demonstrates that PPT can, in fact, meet this goal.  We accomplish this by exploring the development of constitutional standards for the adjudication of sex discrimination claims.  Finally, we summarize our results and underscore the contribution PPT can make to the study of judicial decision making.  

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