Studies of the judiciary seem to be most concerned with how justices make decisions (Langer 2002, Segal & Spaeth 2002, and Knight & Epstein 1996). The research has focused on explaining judicial decisions as a function of fact patterns, the political values of the presiding judges, or institutional design. Each of these theoretical approaches has made important contributions to the field's knowledge, particularly when the U.S. Supreme Court is under consideration. While state courts of last resort have not received quite as much attention as the U.S. Supreme Court, what is known is that factors that seem to be important at the national level are not quite as important at the state level. For instance, much research has been done to show that the political values of U.S. Supreme Court Justices impact their decisions, but "we know for a fact that partisanship among state jurists is not strongly uniform across the country" (Carp and Stidham 1990, 269). In the past decade scholars have taken an interest in state courts, partly due to the revival of the institutional approach (Clayton and Gillman 1999), improved access to data--particularly the State Supreme Court Data Project undertaken by Paul Brace and Melinda Gann Hall--and the active role taken by such organizations as the National Center for State Courts. This paper seeks to build upon this acquired knowledge by asking the question: How does a state's conception of law influence judges?
The development of the American common law system has received only minor attention from political science. Since the 1950's the topic has been nearly ignored in the discipline. However, this trend seems to be changing as a number of studies have begun to focus on the common law, its role in our nation's founding, and the political implications of its subsequent modification since the founding (Stoner 1992 and 2003). This paper is concerned with the last strand of inquiry by examining how the common law influences the decisions of judges at the state level. While there have been historical studies on this topic (Horwitz 1977 and Nelson 1994) this is the first study to quantitatively assess the impact common law has on judges. This paper tests the hypothesis of common law supporters who say the common law is a safeguard which protects individual liberty with respect to community interest. I examine state court of last resort (CLR) decisions on cases that appeal jury verdicts on due process grounds. I employ a common law measure to examine if a state's conception of law has an impact on CLR decisions in these cases.
By concerning itself with how the conception of law affects the behavior of judges, this study will add to the already extensive body of literature which informs our knowledge of judicial behavior. I seek not to refute, but to add an additional layer to what we already know in order to paint a fuller picture of judicial decision making in an effort to inform our discussion about the relationship between formal institutions and the law. This study investigates these questions by asking what impact the common law has on judicial decision making in state courts of last resort.
II. Defining Common Law and How it is Measured
This study considers how the conception of law affects judicial behavior, in that the common law is an indication of a state's conception of law. The measure for the common law employed in this study is a dichotomous variable that reflects whether a state has maintained or rejected crimes defined at common law. But, before a discussion of the measure, a discussion of how the common law is conceptualized in this study must come first.
Any reliable definition of the common law is a description of what it is and where it came from for, as this paper will only briefly show, attempts to define the common law in a dictionary sense will only gloss over the important nuances that characterize it. …