Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-18T20:53:48.841Z Has data issue: false hasContentIssue false

Network Analysis and the Law: Measuring the Legal Importance of Precedents at the U.S. Supreme Court

Published online by Cambridge University Press:  04 January 2017

James H. Fowler
Department of Political Science, University of California, San Diego, Social Sciences Building 383, 9500 Gilman Drive #0521, La Jolla, CA 92093-0521. e-mail: (corresponding author)
Timothy R. Johnson
Department of Political Science, University of Minnesota, Twin Cities, 1414 Social Sciences Building, 267 19th Ave. South, Minneapolis, MN 55455. e-mail:
James F. Spriggs II
Department of Political Science, Washington University in St. Louis, Campus Box 1063, One Brookings Drive, St Louis, MO 63130. e-mail:
Sangick Jeon
Department of Political Science, Stanford University, 616 Serra Street, Encina Hall West, Room 100, Stanford, CA 94305-6044. e-mail:
Paul J. Wahlbeck
Department of Political Science, George Washington University, 1922 F Street, N.W. Suite 401, Washington, DC 20052. e-mail:


We construct the complete network of 26,681 majority opinions written by the U.S. Supreme Court and the cases that cite them from 1791 to 2005. We describe a method for using the patterns in citations within and across cases to create importance scores that identify the most legally relevant precedents in the network of Supreme Court law at any given point in time. Our measures are superior to existing network-based alternatives and, for example, offer information regarding case importance not evident in simple citation counts. We also demonstrate the validity of our measures by showing that they are strongly correlated with the future citation behavior of state courts, the U.S. Courts of Appeals, and the U.S. Supreme Court. In so doing, we show that network analysis is a viable way of measuring how central a case is to law at the Court and suggest that it can be used to measure other legal concepts.

Research Article
Copyright © The Author 2007. Published by Oxford University Press on behalf of the Society for Political Methodology 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Albert, Reka, and Barabasi, Albert-Laszlo. 2002. Statistical mechanics of complex networks. Reviews of Modern Physics 74: 4797.CrossRefGoogle Scholar
Aldisert, Rugero J. 1990. Precedent: What it is and what it isn't; when do we kiss it and when do we kill it? Pepperdine Law Review 17: 605–36.Google Scholar
Allen, Carleton Kemp. 1964. Law in the making. 7th ed. New York: Clarendon Press.Google Scholar
Biskupic, Joan, and Witt, Elder. 1997. Congressional quarterly's guide to the U.S. Supreme Court. 3rd ed. Washington, DC: CQ Press.Google Scholar
Bonacich, Phillip. 1972. Factoring and weighing approaches to clique identification. Journal of Mathematical Sociology 2: 113–20.Google Scholar
Bonacich, Phillip. 1987. Power and centrality: A family of measures. American Journal of Sociology 92: 1170–82.Google Scholar
Caldeira, Gregory A. 1985. The transmission of legal precedent: A study of state Supreme Courts. American Political Science Review 79: 178–93.Google Scholar
Carmines, Edward G., and Zeller, Richard A. 1979. Reliability and validity assessment. Newbury Park, CA: Sage.CrossRefGoogle Scholar
Chandler, Seth J. 2005. The network structure of Supreme Court jurisprudence. In public law and legal Theory series. Report 2005-W-01, 26. Houston, TX: University of Houston Law Center.Google Scholar
Cross, Frank B., Smith, Thomas A., and Tomarchio, Antonio. 2006. Determinants of cohesion in the supreme court's network of precedents. San Diego Legal Studies Paper No. 07-67. Social Science Research Network: (accessed May 15, 2007).CrossRefGoogle Scholar
Douglas, William O. 1979 [1949]. Stare decisis. In Courts, judges, and politics: An introduction to the judicial process, ed. Murphy, Walter F. and Herman Pritchett, C., 6671. New York: Random House.Google Scholar
Dworkin, Ronald M. 1986. Law's empire. Cambridge: Belknap Press.Google Scholar
Epstein, Lee, and Segal, Jeffrey A. 2000. Measuring issue salience. American Journal of Political Science 44: 6683.CrossRefGoogle Scholar
Fowler, James H. 2006. Connecting the Congress: A study of cosponsorship networks. Political Analysis 14: 456–87.Google Scholar
Freeman, Linton C. 1979. Centrality in social networks: Conceptual clarification. Social Networks 1: 215–39.Google Scholar
Friedman, Lawrence M., Kagan, Robert A., Cartwright, Bliss, and Wheeler, Stanton. 1981. State Supreme Courts: A century of style and citation. Stanford Law Review 33: 773818.Google Scholar
Gibson, James L. 1997. United States Supreme Court judicial database, phase II: 1953-1993. Ann Arbor, MI: Inter-University Consortium for Political and Social Research.Google Scholar
Hall, Kermit L. 1999. The Oxford guide to United States Supreme Court decisions. New York: Oxford University Press.Google Scholar
Hansford, Thomas G., and Spriggs, James F. II. 2006. The politics of precedent on the U.S. Supreme Court. Princeton, NJ: Princeton University Press.CrossRefGoogle Scholar
Hellman, Arthur D. 1983. Error correction, lawmaking, and the Supreme Court's exercise of discretionary review. University of Pittsburgh Law Review 44: 795877.Google Scholar
Holmes, Oliver Wendell Jr. 1991 [1881]. The common law. New York: Dover Publications.Google Scholar
Johnson, Charles A. 1987. Law, politics, and judicial decision making: Lower federal court uses of Supreme Court decisions. Law and Society Review 21: 325–40.Google Scholar
Jones, Harry W. 1975. Our uncommon common law. Tennessee Law Review 42: 443–63.Google Scholar
Kempin, Frederick G. 1959. Precedent and stare decisis: The critical years, 1800 to 1850. American Journal of Legal History 3: 2854.Google Scholar
Klein, David E. 2002. Making law in the United States Courts of Appeals. New York: Cambridge University Press.Google Scholar
Kleinberg, Jon M. 1999. Authoritative sources in a hyperlinked environment. Journal of the Association for Computing Machinery 46(5): 604632.Google Scholar
Kosma, Montgomery N. 1998. Measuring the influence of Supreme Court justices. Journal of Legal Studies 27: 333–72.Google Scholar
Landes, William M., Lessig, Lawrence, and Solimine, Michael E. 1998. Judicial influence: A citation analysis of federal courts of appeals judges. Journal of Legal Studies 27: 271332.Google Scholar
Landes, William M., and Posner, Richard A. 1976. Legal precedent: A theoretical and empirical analysis. Journal of Law and Economics 19: 249307.Google Scholar
Levi, Edward H. 1949. An introduction to legal reasoning. Chicago: University of Chicago Press.Google Scholar
Lindquist, Stefanie A., and Cross, Frank B. 2005. Empirically testing Dworkin's chain novel theory: Studying the path of precedent. New York University Law Review 80: 1156–206.Google Scholar
Maltz, Earl. 1988. The nature of precedent. North Carolina Law Review 66: 367–92.Google Scholar
McIntosh, Wayne, Cousins, Ken, Rose, James, Simon, Steve, Evans, Mike, Karnes, Kimberly, McTague, John, and Pearson-Merkowitz, Shanna. 2005. Using information technology to examine the communication of precedent: Initial findings and lessons from the CITE-IT project. Paper presented at the Annual Meeting of the Western Political Science Assocation, Oakland, CA.Google Scholar
Merryman, John Henry. 1954. The authority of authority: What the California Supreme Court cited in 1950. Stanford Law Review 6: 613–73.Google Scholar
Merryman, John Henry. 1977. Toward a theory of citations: An empirical study of the citation practice of the California Supreme Court in 1950, 1960, and 1970. Southern California Law Review 50: 381428.Google Scholar
Post, David G., and Eisen, Michael B. 2000. How long is the coastline of the law? Thoughts on the fractal nature of legal systems. Journal of Legal Studies 29: 545–84.Google Scholar
Powell, Lewis F. Jr. 1990. Stare decisis and judicial restraint. Washington and Lee Law Review 47: 281–90.Google Scholar
Proctor, C. H., and Loomis, C. P. 1951. Analysis of sociometric data. In Research methods in social relations, ed. Holland, P.W. and Leinhardt, S., 561–86. New York: Dryden Press.Google Scholar
Rapp, Cynthia. 2004. A collection of in chambers opinions by the justices of the Supreme Court of the United States. Washington, DC: Green Bag Press.Google Scholar
Redner, S. 1998. How popular is your paper? An empirical study of the citation distribution. European Physical Journal B 4: 131–4.Google Scholar
Richards, Mark J., and Kritzer, Herbert M. 2002. Jurisprudential regimes in Supreme Court decision making. American Political Science Review 96: 305–20.Google Scholar
Schauer, Frederick. 1987. Precedent. Stanford Law Review 39: 571605.Google Scholar
Sirico, Louis J. Jr. 2000. The citing of law reviews by the Supreme Court, 1971-1999. Indiana Law Journal 75: 1009–39.Google Scholar
Spriggs, James F. II, and Hansford, Thomas G. 2000. Measuring legal change: The reliability and validity of Shepard's citations. Political Research Quarterly 53: 327–41.Google Scholar
Wahlbeck, Paul J. 1998. The development of a legal rule: The federal common law of public nuisance. Law & Society Review 32: 613–37.Google Scholar
Wald, Patricia M. 1995. The rhetoric and the results of rhetoric: Judicial writings. University of Chicago Law Review 62: 1371–419.Google Scholar
Wasby, Stephen L., Peterson, Steven, Schubert, James, and Schubert, Glendon. 1992. The per curiam opinion: Its nature and functions. Judicature 76: 2938.Google Scholar
Wasserman, Stanley, and Faust, Katherine. 1994. Social network analysis: Methods and applications. New York: Cambridge University Press.Google Scholar