Michael Klarman is a legal historian who likes to explore the kinds of questions that political scientists ask about the Supreme Court. In his extraordinary book From Jim Crow to Civil Rights he addresses a topic that has been dear to the hearts of many judicial behaviorists: are Supreme Court decisions motivated by legal considerations or by non-legal considerations, such as the justices' personal attitudes or other political calculations? When behaviorists take on this question they begin by developing measures of law and judicial attitudes (e.g., see here and here). Klarman opted for an in-depth case study (see also his draft essay here).
Specifically, he identified the justices who participated in Brown v. Board of Education and collected evidence regarding their personal, political, and legal views on segregation. Not surprisingly, Klarman found that many of the justices who personally considered segregation to be immoral also adopted legal positions that treated segregation as unconstitutional. In some cases the data were ambiguous, and the best Klarman could do was offer informed speculation -- for example, as to whether Cold Warriors Burton and Minton (who had not previously exhibited support for the active judicial protection of civil rights and liberties) sincerely believed that segregation violated equal protection or were instead swayed primarily by the Cold War imperatives of the case. Klarman also made a very persuasive case that, for Justices Frankfurter and Jackson, Brown represented a clear clash between legal considerations (which, in their judgment, argued in favor of upholding Plessy) and personal/political considerations (which they believed argued in favor of overruling Plessy). The overall result was a richly textured discussion of how personal, political, and legal factors influenced the outcome in Brown.
Klarman's analysis undoubtedly provokes questions about his interpretation of the evidence or the generalizability of his findings; that's the appropriate fate of all studies. But one thing about his analysis is incontrovertible -- it is empirical.
As scholars begin to map out the contours of Empirical Legal Studies (ELS), it is vital to agree at the outside that empiricism takes a variety of forms and does not privilege the idea of measurement over other ways to collect and assess data. Of course, quantification and statistical analysis are indispensable tools, and it's great to admire ELS Workshops that promote competency in the use of these tools. But advocates of ELS must not equate "research methods" with the particular practices preferred by people who, temperamentally, like to count and model, and this means doing our best to ensure that workshops, conferences, and journals which display the ELS banner are inclusive of the broad spectrum of empirical research traditions.
When we learned that the 2006 meeting of the AALS was to be devoted to ELS, Mark Graber noted that "[w]hen law professors participate in groups committed to empirical legal studies, ... they should be aware that most social scientists would not limit such analysis to rational choice and statistics and those who tell them otherwise are making self-serving comments on behalf of a particular tribe rather than speaking for the discipline." I don't know if anyone is actually telling them this -- that's an empirical question and I have not done the research -- but to avoid any misleading impressions let's all agree, up front, that any speaker who uses "empirical" in a way that excludes (for example) historical, ethnographic, or interpretive methods is either completely unclear on the concept or is using the concept as a euphemism for her/his personal preferences.