Law’s Algorithm

This Article offers a historical, theoretical, and practical perspective on law as an information technology. Law fundamentally concerns information—providing information to the community about the content of legal norms and, at least in its common law form, eliciting information about the world from the disputes before a court. This Article first surveys law’s history as an information technology and shows how law is changed by the information technology of its day. It then applies information theory to understand how the computer—the key technology of our day— is changing how practitioners conduct legal search and thereby which forms of law are the most efficient. Information theory focuses on the signal to noise ratio of communication. The key to creating a better computerized legal search engine is to reduce the signal to noise ratio in the link between the user and the search engine. As this ratio decreases, this Article shows that legal search translates the uncompressed form of legal information into an algorithm for predicting what the law will be in a particular situation. The ongoing improvement in legal search is transforming the optimal form of the law by changing the cost of finding it. It rebalances the weights in the classic debate between rules and standards. In particular, exponential increases in computational power make standards relatively more attractive than rules by decreasing the costs of their application. These same increases also allow us to embed information gathering processes within the law itself by creating what we call “dynamic rules.” Dynamic rules are rules that change automatically in response to changing empirical information. Legislatures are already beginning to enact such rules. Since this Article posits that legal standards and dynamic rules are likely to be important forms of legal rules in the coming era, this Article closes with a comparison of their relative costs and benefits. * George C. Dix Professor in Constitutional Law, Northwestern University School of Law. We are grateful to Robert C. Berring, Jr., Jonathan C. Carlson, Nelson Lund, Andrew Meerkin, Robert T. Miller, Mark L. Movsesian, Mark J. Osiel, Max M. Schanzenbach, and participants in a conference on law and information technology at the Law and Economics Center at George Mason University School of Law and at faculty workshops at the University of Iowa College of Law and Northwestern University Law School for helpful comments on previous drafts. † President, Fantasy Journalist, Inc.; J.D., Northwestern University School of Law. 1 McGinnis and Wasick: Law’s Algorithm Published by UF Law Scholarship Repository, 2015 992 FLORIDA LAW REVIEW [Vol. 66 INTRODUCTION 992 I. THE INFORMATION TECHNOLOGY OF LAW—A BRIEF HISTORY 997 A. Top-Down Versus Distributed Forms of Legal Ordering as Information Structures 998 B. The Development of Law as an Information Technology 1000 C. The Tension Created by Limits of Information Capacity 1006 II. CREATING LAW’S ALGORITHM 1009 A. The Beginning of Computerized Legal Search 1009 B. The Future Improvement of Computerized Legal Search 1013 1. Moore’s Law and Powerful Natural Language Search 1013 2. The Practical Effects of Accurate Natural Language Search 1017 C. Information Theory and Advanced Legal Search 1019 III. THE MOVE TO STANDARDS AND DYNAMIC RULES 1026 A. Informational Capability and Its Effect on the Rules Versus Standards Debate 1026 1. Background of the Rules Versus Standards Debate 1026 2. How ALE Search Makes Standards More Attractive by Decreasing the Cost of Finding the Law 1033 3. Example: The Montana Speed Limit Experiment 1035 4. Applying ALE to Already Existing Standards 1037 B. Dynamic Rules 1039 C. Standards Versus Dynamic Rules 1045 CONCLUSION 1048