Statistics for Social Science and Public Policy Advisors: S. Fienberg D. Lievesley J. Rolph Springer Science+Business Media, LLC Statistics for Social Science and Public Policy DevlinlFienberglResnicklRoeder (Eds.): Intelligence, Genes, and Success: Scientists Respond to The Bell Curve. ZeisellKaye: Prove It with Figures: Empirical Methods in Law and Litigation. Hans Zeisel David Kaye Prove It with Figures Empirical Methods in Law and Litigation With a Foreword by Jack B. Weinstein , Springer Hans Zeisel David Kaye (deceased) College of Law Arizona State University Tempe, AZ 85287 USA Advisors Stephen Fienberg John Rolph Department of Statistics Graduate School of Business Carnegie-Mellon University Department of Information and Pittsburgh, PA 15213 Operations Management University of Southern California Los Angeles, CA 90089 Denise Lievesley ESRC Data Archive University of Essex Colchester, Essex C04 3SQ United Kingdom Library of Congress Cataloging-in-Publication Data Zeisel, Hans. Prove it with figures : empirical methods in law and litigation I Hans Zeisel, David Kaye with a foreword by Jack B. Weinstein. p. cm. Includes bibliographical references and index. ISBN 978-1-4612-7300-4 ISBN 978-1-4612-1824-1 (eBook) DOI 10.1007/978-1-4612-1824-1 1. Law - United States - Statistical methods. 2. Law - United States-Methodology. 3. Social sciences-Research-Law and legislation-United States. 1. Kaye, D.H. (David H.), 1947- II. Title. KF320.S73Z45 1997 349.73 '07'27 -dc21 97-9827 Printed on acid-frec paper. © 1997 Springer Science+Business Media New York Originally published by Springer-Verlag New York, Ine. in 1997 Softcover reprint oftbe hardeover Ist edition 1997 AlI rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use of general descriptive names, trade names, trademarks, etc., in this publication, even if the former are not especially identified, is not to be taken as a sign that such names, as understood by the Trade Marks and Merchandise Marks Act, may accordingly be used frecly byanyone. Production managed by Victoria Evarretta; manufacturing supervised by Jeffrey Taub. Photocomposed copy prepared by the author using Wordperfect 7.0. 987654321 ISBN 978-1-4612-7300-4 To the princely memory of Harry Kalven, the Harry A. Bigelow Professor of Law at the University of Chicago Law School. By his deep interest in and understanding of the place of empirical research in the law, he played a major role in its development and acceptance. H.Z. Foreword Judges, lawyers, academics, law students, legislators, the business community, and the public at large are presented in this volume with a clearly written and fascinating primer on fact-fmding for policymaking or adjudication. Hans Zeisel's studies represent the blending of the best of European and American sociology, psychology, and other social sciences with jurisprudence. David Kaye picks up Zeisel' s torch of statistically based fact-fmding, illuminating the latest developments in the emerging field of legal statistics. Both tell us how to avoid being misled by field studies and statistical and scientific studies, while squeezing the most valuable and reliable data that can conveniently be made available. Zeisel and Kaye open the windows of our stuffy chambers where decision makers have too often relied solely on their own limited experiences and biases and those embodied in equally limited precedents or policies. "Look out on the real world as it is," they exhort, "and see the effects of what you do or plan to do on real people and real institutions." "Observe, experiment and use the criteria of statisticians and scientists in evaluating data," they instruct. They explain how it should be done, what the pitfalls are, and they identify the limits of knowledge and prediction. Perhaps most importantly, they provide candor in recognizing the limits of statistical and scientific knowledge and how to determine what information is necessary for greater precision. The authors have been involved in myriad studies, and they discuss all types - controlled, randomized, observational, epidemiological, and those based on other methodologies. Embodied in the book are more than a score of case histories selected from many they have been responsible for. They include analyses of the death penalty, jury selection, mass torts, and present and future vaccine evaluations. Each story is told with enough detail to be fascinating and instructive, yet not so much as to be tedious. I have had the pleasure of working with both authors. When I was hired as reporter to the Tweed Commission in the mid-1950s to revise New York's civil practice and court procedures, I needed help to tell us how the system was working. Hans Zeisel was recommended by the leading sociologists of the day for his theoretical knowledge and his practical experience in the new commercial field of market research. As a professor viii Foreword at the University of Chicago Law School, he had been conducting a comprehensive study of the American jury. There was, at fITst, great opposition from judges to his field studies. Zeisel' ~ charm and great skills soon pried open the courthouses. Teased from limited data were major findings published in the book Delay in the Courts. This and others of his I works have opened wide the courts to many subsequent empirical works on the law.2 Like many other practitioners and scholars, I constantly turned to him for advice. David Kaye's work has been exemplary as an outstanding teacher, lecturer, and the author of many monographs and articles in evidence, law and social science, and legal statistics, among other subjects.3 Over the years, I, as well as many others, have turned to him for help in understanding science, statistics, and the law. No one has a reputation or skills superior to his in the fields in which he and his coauthors have collaborated. Despite its imposing title and subject matter, this book can be read as an engrossing and accessible introduction to the subject by those with but a passing interest in the field. Yet, so incisive and sophisticated is the analysis that it will join the handful of basic references on the shelves of every judge and litigator who must deal with science and statistics. There are almost none in today's and tomorrow's world of law who will not need to grapple regularly with these subjects. Jack B. Weinstein Senior United States District Judge Eastern District of New York Preface In the fall of 1951, in New York City, I received a telephone call and later a visit from Edward H. Levi, then dean of the University of Chicago Law School. He had persuaded the Ford Foundation to give the law school a major grant for exploring the potential usefulness of social science research for the law. "We were looking for a common-law lawyer to help us, who knew everything about social science research [the "everything" was accompanied by a gesture of uncertainty], but could not find one. You are at least a European lawyer. You are our second choice. Do you want to come?" I came, and the present text is part of the harvest. The first years of the four decades I have spent at the University of Chicago Law School were devoted almost exclusively to developing research that would be substantial enough to regenerate broad interest in factual research of legal problems. The American Jury! and its related publications,2 did just that. Other law schools also ventured into this borderland of the law, and eventually I taught a course that I titled "Social Science Research in Litigation." The students seemed to enjoy it. The present text is an effort to codify the learning in this field systematically. It is intended to provide law teachers with one possible model for teaching the subject that in the meantime has become an important, if still peripheral, law school tradition. For this ambitious enterprise I have won the collaboration of a kindred spirit and dear friend, David Kaye, now Regents' Professor at the College of Law of Arizona State University. Social science has been understood in many ways. For the purposes of the present text, we mean it to refer to the tool chest social scientists use in their efforts to unearth or reinforce new insights into our social life. The vistas are not often wide; as a rule, their range is modest, but these limitations are counterbalanced by precise observation and analysis. Originally, we wanted to call our text Social Science Research in Litigation. While this has become the more acceptable name, we hesitated. The law's tool chest overlaps with other sciences; experimental and observational studies are used in many sciences and inquiries, and statistics has become the universal quantitative language in all scientific fields. And, this book discusses issues in epidemiology, toxicology, medicine, and many x Preface other disciplines. To call our endeavors empirical or factual research seemed to us the more correct description. The degree of familiarity to which we want to bring the student's understanding of the tool chest is limited. The student will not be expected to master each tool, but to appreciate its structure and purpose, so that when the time comes, the lawyer can discuss it intelligently with an expert. The discussion of the tool chest is interlaced with its application in litigation, or legal research, by administrative agencies, or simply research with a bearing on legal problems. At times, the explication of a tool continues without such examples because the tool has not yet found its footing in the law. But since the primary objective of this text is to acquaint the student with the tool chest, even if its legal role may lie in the future, such passages are unavoidable. David Kaye and I have occasionally done some consulting work with litigators. We have drawn on that experience in instances where, we like to think, our contribution has advanced research methodology and, at times, even the law. Legal ,disputes, at the ground level, rest on two foundations: the underlying facts and the law that pertains to them. The contribution of social science research is to render the fact-finding process more precise. That use in litigation is growing. In the process, the tools have sharpened, partly because the courts have had the opportunity of examining some of them and have expressed their approval or disapproval, as the case may be. This text is designed for the practicing lawyer as well as for students and their teachers. The topics considered here allow the practitioner, faced with a certain problem, to learn whether there are approaches that might help to prove an important point. The examples and accompanying discussions, as well as the selected references at the end of each chapter, may assist in developing the vocabulary and perspective for dealing with relevant experts. The result, we hope, will be not merely an increase in the use of systematic empirical methods in law and litigation, but an improvement in the quality of decisions and in the understanding of the issues under investigation. Hans Zeisel Chicago, lllinois, 1992 In 1980, when I was teaching at the University of Southampton, I received a letter from Hans Zeisel. Hans wanted to know whether I might collaborate Preface xi on a textbook on social science methods for law students. Hans never told me why he contacted me, a young law professor who had had no contact with him or any of his colleagues at the University of Chicago. We met in the O'Hare airport when I returned to the states. Hans escorted me to his Hyde Park apartment, and promptly made me part of his extended family. We never completed the project Hans had in mind. Hans had retired from full-time teaching, but not from pursuing, with his inimitable verve and intensity, a great many interests. He wrote more articles and books. Eminent trial attorneys sought his counsel in major litigation, both commercial and pro bono publico. Work on "the book" or "our book," as he generously called it, came in fits and starts until his last years. Then, he returned to the project with determination, working on it until the fmal weeks of his long and fruitful life. This book is based on the drafts that Hans left. I have edited them and filled in various gaps as best I could, but the Hans I knew would not have been satisfied. He would have wanted - and achieved - something better. Still, I hope that I have moved his fmal efforts in the direction that he would have wanted and that he would have approved of my additions to Chapters 2, 3, 5, and 12, and of Chapters 4, 6, and 13, most of which were written without his critical eye and keen mind. David H. Kaye Tempe, Pulzona, 1997