An Introduction to Empirical Legal Research

Is the death penalty a more effective deterrent than lengthy prison sentences? Does a judge's gender influence their decisions? Do independent judiciaries promote economic freedom? Answering such questions requires empirical evidence, and arguments based on empirical research have become an everyday part of legal practice, scholarship, and teaching. In litigation judges are confronted with empirical evidence in cases ranging from bankruptcy and taxation to criminal law and environmental infringement. In academia researchers are increasingly turning to sophisticated empirical methods to assess and challenge fundamental assumptions about the law.

As empirical methods impact on traditional legal scholarship and practice, new forms of education are needed for today's lawyers. All lawyers asked to present or assess empirical arguments need to understand the fundamental principles of social science methodology that underpin sound empirical research. An Introduction to Empirical Legal Research introduces that methodology in a legal context, explaining how empirical analysis can inform legal arguments; how lawyers can set about framing empirical questions, conducting empirical research, analyzing data, and presenting or evaluating the results. The fundamentals of understanding quantitative and qualitative data, statistical models, and the structure of empirical arguments are explained in a way accessible to lawyers with or without formal training in statistics.

Written by two of the world's leading experts in empirical legal analysis, drawing on years of experience in training lawyers in empirical methods, An Introduction to Empirical Legal Research will be an invaluable primer for all students, academics, or practicing lawyers coming to empirical research - whether they are embarking themselves on an empirical research project, or engaging with empirical arguments in their field of study, research, or practice.

Lee Epstein, Provost Professor and Rader Family Trustee Chair in Law & Political Science, University of Southern California,Andrew D. Martin, Professor of Law and Political Science and Director of the Center for Empirical Research in the Law, Washington University, St. Louis

Lee Epstein is the Provost Professor of Law and Political Science and the Rader Family Trustee Chair in Law at the University of Southern California. She has previously held posts at Northwestern University and Washington University, St Louis. Professor Epstein has received twelve grants from the National Science Foundation for her work on law and legal institutions, and has authored or co-authored 15 books, including The Behavior of Federal Judges: A Theoretical and Empirical Study of Rational Choice (2013, with W.M. Landes and R.A. Posner), the Constitutional Law for a Changing America books (with T.G. Walker), and The Choices Judges Make, with J. Knight, which won the Pritchett Award for the Best Book on Law and Courts and the 2010 Lasting Contribution Award "for a book or journal article, 10 years or older, that has made a lasting impression on the field of law and courts."


Andrew Martin is Professor of Law and Vice Dean at the Washington University School of Law. He is also the Founding Director of the Center for Empirical Research in the Law, and Professor of Political Science in Arts and Sciences at the University. Professor Martin has received eight grants from the National Science Foundation, and is the author of numerous articles in prominent law and social science journals. Together with Professor Epstein he teaches the Annual Conducting Empirical Legal Scholarship workshop, offering formal training in the design, conduct, and assessment of empirical studies and the use of statistical software to analyze and manage data.

1. Some Preliminaries
Part I: Designing Research
2. Questions, Theories, Observable Implications
3. Measurement
Part II: Collecting and Coding Data
4. Collecting Data
5. Coding Data
Part III: Analyzing Data
6. Summarizing Data
7. Statistical Interference
8. Regression Analysis: The Basics
9. Multiple Regression Analysis and Related Methods
Part IV: Communicating Data and Results
10. General Principles for Communicating and Visualizing Data
11. Strategies for Presenting Data and Statistical Results
12. Concluding Remarks
Appendix A: Supplementary Materials