Slides Available for Katz and Bommarito: Network Analysis and Law: Introductory Tutorial

Slides have been posted for “Network Analysis and Law: Introductory Tutorial”, taught by Professor Dr. Daniel Martin Katz of Michigan State University College of Law and Michael J. Bommarito II of Computational Legal Studies, on 13 December 2011 in Vienna, Austria, at JURIX 2011: The 24th International Conference on Legal Knowledge and Information Systems.

Here is the outline of the tutorial:

Network Analysis: An Extended Primer

Advanced Network Science Topics

• Community Detection
• ERGM / P* Models
• Social Epidemiology

Network Analysis and Law

• Legal Elites
• Diffusion and Other Related Processes
• Legal Doctrine and Legal Rules

The Frontier of Network Analysis and Law

• Distance Measures for Dynamic Citation Networks
• Dynamic Community Detection
• The Judicial Collaborative Filter (Judge Aided Info Retrieval)

For more information, please see the slides.

HT @computational.

Boulet, Mazzega, and Bourcier on A Network Approach to the French System of Legal Codes Part 1

Dr. Romain Boulet of UMR ESPACE-DEV, IRD; Dr. Pierre Mazzega of UnB/IRD and UPS (OMP), CNRS, IRD; and Dr. Danièle Bourcier of CERSA CNRS, have published A network approach to the French system of legal codes—part I: analysis of a dense network, Artificial Intelligence and Law, 19, 333-355 (2011). Here is the abstract:

We explore one aspect of the structure of a codified legal system at the national level using a new type of representation to understand the strong or weak dependencies between the various fields of law. In Part I of this study, we analyze the graph associated with the network in which each French legal code is a vertex and an edge is produced between two vertices when a code cites another code at least one time. We show that this network distinguishes from many other real networks from a high density, giving it a particular structure that we call concentrated world and that differentiates a national legal system (as considered with a resolution at the code level) from small-world graphs identified in many social networks. Our analysis then shows that a few communities (groups of highly wired vertices) of codes covering large domains of regulation are structuring the whole system. Indeed we mainly find a central group of influent codes, a group of codes related to social issues and a group of codes dealing with territories and natural resources. The study of this codified legal system is also of interest in the field of the analysis of real networks. In particular we examine the impact of the high density on the structural characteristics of the graph and on the ways communities are searched for. Finally we provide an original visualization of this graph on an hemicyle-like plot, this representation being based on a statistical reduction of dissimilarity measures between vertices. In Part II (a following paper) we show how the consideration of the weights attributed to each edge in the network in proportion to the number of citations between two vertices (codes) allows deepening the analysis of the French legal system.

Katz and Bommarito to Teach Network Analysis and Law Tutorial @ Jurix 2011

A tutorial on “Network Analysis and Law”, taught by Professor Dr. Daniel Martin Katz of Michigan State University College of Law and Michael J. Bommarito II of Computational Legal Studies, will be held 13 December 2011 in Vienna, Austria, at JURIX 2011: The 24th International Conference on Legal Knowledge and Information Systems.

Here are the goals of the tutorial:

• To introduce a variety of concepts from complex systems and network science
• To outline potential applications of network science in legal studies and positive legal theory
• To highlight possible uses of network metadata to enrich legal informatics sub-fields such as information retrieval
• To examine the application of various network based epidemiological / diffusion models
• To introduce participants to various theoretical and empirical network science software platforms

For more information, please see the announcement.

HT @computational.

April 22: Workshop on Law and Computation

A Workshop on Law and Computation will be held 22 April 2011 at the University of Houston Law Center in Houston, Texas, USA.

The workshop is hosted by the Law Center’s Program on Law and Computation.

According to the workshop announcement:

The workshop will provide opportunities to show ways in which advanced computation can aid in the understanding of law and will demonstrate techniques from the fields of statistics, evolutionary computation, data mining, artificial intelligence, computational linguistics, and networks.

Presenters at the workshop are scheduled to include:

• Dr. Stephen Wolfram of Wolfram Research;
• Professor Paul Ohm of the University of Colorado School of Law;
• Carl Malamud of Public.Resource.Org and the Law.Gov legal open government data movement;
• Daniel Martin Katz of the University of Michigan’s Center for the Study of Complex Systems and Computational Legal Studies;
• Emile de Maat of the Leibniz Center for Law at the University of Amsterdam;
• Michael Bommarito of Computational Legal Studies;
• Prof. Alan Izenman of Temple University;
• Mark Kotanchek of Evolved Analytics;
• Prof. Chris Reed of the University of Dundee;
• Prof. Ted. Sichelman of the University of San Diego; and
• Prof. Harry Surden of the University of Colorado.

For more information, please see the workshop announcement.

Bommarito, Katz, and Isaacs: An Empirical Survey of the Population of United States Tax Court Written Decisions

Michael J. Bommarito II and Daniel Martin Katz, both of the University of Michigan’s Center for the Study of Complex Systems and Computational Legal Studies, and Jillian Isaacs-See of BDO USA, LLP, have published An Empirical Survey of the Population of United States Tax Court Written Decisions, Virginia Tax Review, 30, 523-557 (2011). Here is the abstract:

What can empirical data tell us about the jurisprudence of United States Tax Court? Which sections of the Internal Revenue Code are most frequently cited and has recent tax legislation sparked change in the Tax Court’s decisions? This article presents an analysis of the citation practices of the United States Tax Court between 1990 and 2008. While previous citation studies focus on case-to-case citations, we modify this approach to focus on statutory citations, which better capture the nature of tax jurisprudence. By applying techniques from computer science, we collect and analyze more than 11,000 decisions and 244,000 statutory citations authored by the United States Tax Court between 1990 and 2008. Our approach includes both a static and longitudinal analysis of the most cited Internal Revenue Code sections. In addition, we carry out a network analysis of these case-to-statute citations to uncover patterns in citation practices, concept relationships, and legislative acts. This article answers the call for greater empiricism in tax scholarship and paves the way for future research on Tax Court jurisprudence.

Liu & Shih on Hybrid-Patent Classification Based on Patent-Network Analysis

Professor Dr. Duen-Ren Liu and Meng-Jung Shih, both of National Chiao Tung University Institute of Information Management, have published Hybrid-patent classification based on patent-network analysis, forthcoming in Journal of the American Society for Information Science and Technology (JASIST). Here is the abstract:

Effective patent management is essential for organizations to maintain their competitive advantage. The classification of patents is a critical part of patent management and industrial analysis. This study proposes a hybrid-patent-classification approach that combines a novel patent-network-based classification method with three conventional classification methods to analyze query patents and predict their classes. The novel patent network contains various types of nodes that represent different features extracted from patent documents. The nodes are connected based on the relationship metrics derived from the patent metadata. The proposed classification method predicts a query patent’s class by analyzing all reachable nodes in the patent network and calculating their relevance to the query patent. It then classifies the query patent with a modified k-nearest neighbor classifier. To further improve the approach, we combine it with content-based, citation-based, and metadata-based classification methods to develop a hybrid-classification approach. We evaluate the performance of the hybrid approach on a test dataset of patent documents obtained from the U.S. Patent and Trademark Office, and compare its performance with that of the three conventional methods. The results demonstrate that the proposed patent-network-based approach yields more accurate class predictions than the patent network-based approach.

Slides Available for Bommarito et al., Distance Measures for Dynamic Citation Networks @ Political Networks Conference 2010

Michael James Bommarito II, Daniel Martin Katz, & Jon Zelner, all of the University of Michigan at Ann Arbor, Center for Study of Complex Systems, & Professor James H. Fowler of the University of California, San Diego, Department of Political Science, presented their paper entitled Distance Measures for Dynamic Citation Networks at the Political Networks Conference 2010, held 19-21 May 2010 at the Duke University Department of Political Science, in Durham, North Carolina, USA.

Click here for the presentation slides at Computational Legal Studies.

Here is the abstract of the paper:

Acyclic digraphs arise in many natural and artificial processes. Among the broader set, dynamic citation networks represent a substantively important form of acyclic digraphs. For example, the study of such networks includes the spread of ideas through academic citations, the spread of innovation through patent citations, and the development of precedent in common law systems. The specific dynamics that produce such acyclic digraphs not only differentiate them from other classes of graphs, but also provide guidance for the development of meaningful distance measures. In this article, we develop and apply our sink distance measure together with the single-linkage hierarchical clustering algorithm to both a two-dimensional directed preferential attachment model as well as empirical data drawn from the first quarter century of decisions of the United States Supreme Court. Despite applying the simplest combination of distance measures and clustering algorithms, analysis reveals that more accurate and more interpretable clusterings are produced by this scheme.

Lupu & Voeten on The Role of Precedent at the European Court of Human Rights: A Network Analysis of Case Citations

Yonatan Lupu of the University of California, San Diego Department of Political Science and Professor Erik Voeten of the Georgetown University School of Foreign Service, have posted The Role of Precedent at the European Court of Human Rights: A Network Analysis of Case Citations. The authors presented the paper at the 2010 Political Networks Conference, held 19-21 May 2010 at the Duke University Department of Political Science in Durham, North Carolina, USA. Here is the abstract of the paper:

While political scientists have become increasingly interested in the output of international courts, they have paid little attention to the manner by which these courts justify their decisions and develop legal norms. We address these issues through a network analysis of European Court of Human Rights (ECtHR) citations. We argue that, like domestic review courts, the ECtHR uses its legal justifications at least in part to convince “lower” (domestic) courts of the legitimacy of its judgments. Several empirical observations are consistent with this view. First, country-specific factors do not determine the case-law on which the Court relies. Instead, it cites precedent based on the legal issues in the case. Second, the Court is more careful to embed judgments in its existing case law with respect to the more politically sensitive decisions. Third, the court embeds its judgments in case-law more when the respondent government is from a common law legal system where the courts traditionally rely more on similar justifications. In all, we conclude that the ECtHR by and large uses case law to justify its decisions in a way that is similar to domestic review courts. Finally, we highlight the utility of applying network analysis to further study the development of international legal norms.

Thanks to Professor Voeten for the URL of the paper.