A pattern analysis of the second Rehnquist U.S. Supreme Court

doi:10.1073/pnas.1132164100

A pattern analysis of the second Rehnquist U.S. Supreme Court

Lawrence Sirovich†

Laboratory of Applied Mathematics, Department of Biomathematical Sciences, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY 10029

Communicated by Mitchell J. Feigenbaum, The Rockefeller University, New York, NY, April 14, 2003 (received for review March 15, 2003)

Abstract

The second Rehnquist Court has remained unchanged in composition for 8 yr, resulting in a large temporally stable database. This paper reports on a mathematically objective analysis of this ensemble of rulings aimed at extracting key patterns and latent information. Although the rulings of a nine-justice Court require representation in nine dimensions, smaller spaces describe the Court's actions; e.g., a 2D subspace describes the margins of all decisions, and use of Shannon information shows that the Court acts as if composed of 4.68 ideal justices. Comparison is also made with the 1959–1961 and 1967–1969 Warren Courts. Both Warren Courts have remarkable parallels with the Rehnquist Court. In each instance, we present an optimal mapping of the justices between the Courts, which underscores the similarity in the workings of seemingly dissimilar courts.

Footnotes

↵ † E-mail: chico{at}camelot.mssm.edu.
Abbreviation: SVD, single value decomposition.
Note Added in Proof. A quantitative approach to such issues can be found in Martin and Quinn (18).
↵ ‡ Two sites we used are http://supct.law.cornell.edu/supct/index.html and www.findlaw.com/casecode/supreme.html.
↵ § In keeping with the spirit of this paper, we do not consider models based on psychology, behavior, economics, and other such considerations (10).
↵ ¶ Although ``platonic'' is used in the sense of lofty or idealistic, mention might be made of ``platonic solids,'' which refer to the five perfect solids in 3D space, of which one is the cube. In nine-dimensions regular polytopes, the generalization of platonic solids are three in number, of which one is the (hyper) cube with 2⁹ vertices given by (Eq. 1) ref. 11.
↵ ∥ This period contained a substantially larger fraction of per curiam and ambiguous cases than the Rehnquist collection.