I was revisiting some of our old stuff for this Oslo event -early on for us on our #LegalPhysics #LegalAnalytics path – published in Physica A – “By applying our sink clustering method, we obtain a dendrogram of the network’s largest weakly connected component shown in Fig. 4. However, despite their general topical relatedness, these two clusters of cases engage substantively different sub-questions, and are thus appropriately divided into separate clusters. While not a major focus of the docket of the modern court, the early court elaborated a number of important legal concepts through the lens of these admiralty decisions. For example, the red group of cases engages questions of presidential power and the laws of war, as well as general interpretations of the Prize Acts of 1812. Meanwhile, the blue cluster engages questions surrounding tort liability, jurisdiction, and the burden of proof.”
Starting my fall road show across Chicago Area law schools, today I gave the faculty lunch seminar at Depaul University College of Law. I presented our paper on Judicial Decision Making and Stock Market Movements. Thanks to the good folks at Depaul for your thoughtful comments on the paper.
On behalf of my co-authors — next month — I will be presenting at the University of Chicago – Workshop on Judicial Behavior – Organized by Lee Epstein, Frank Easterbrook, Dennis Hutchinson, William Landes and Richard Posner. I think we have a very appropriate UChicago styled paper on Judicial Decision Making and Stock Market Movements.
Tomorrow I will deliver the Thursday Keynote at the Legal Week Strategic Technology Forum in San Diego. I look forward to connecting with old friends and making new friends at the event!
From the article – “We are increasingly thinking that there’s room in legal tech for a Red Hat in legal — companies that really focus on development of software by providing wraparound services, but offer their software open source,” Michael J Bommarito II said.
Our paper is now live in the Journal of Statistical Physics.
This is one of our all time best efforts from a scientific perspective (and it is now 7 years old). We did a rehash of it in our recent paper in the March 31, 2017 edition of Science magazine.
What are some of the key takeaway points?
(1) The Supreme Court’s increasing reliance upon its own decisions over the 1800-1830 window.
(2) The important role of maritime/admiralty law in the early years of the Supreme Court’s citation network. At least with respect to the Supreme Court’s citation network, these maritime decisions are the root of the Supreme Court’s jurisprudence.
(3) The increasing centrality of decisions such as Marbury v. Madison, Martin v. Hunter’s Lessee to the overall network.
The Development of Structure in the SCOTUS Citation Network
The visualization offered above is the largest weakly connected component of the citation network of the United States Supreme Court (1800-1829). Each time slice visualizes the aggregate network as of the year in question.
In our paper entitled Distance Measures for Dynamic Citation Networks, we offer some thoughts on the early SCOTUS citation network. In reviewing the visual above note ….“[T]he Court’s early citation practices indicate a general absence of references to its own prior decisions. While the court did invoke well-established legal concepts, those concepts were often originally developed in alternative domains or jurisdictions. At some level, the lack of self-reference and corresponding reliance upon external sources is not terribly surprising. Namely, there often did not exist a set of established Supreme Court precedents for the class of disputes which reached the high court. Thus, it was necessary for the jurisprudence of the United States Supreme Court, seen through the prism of its case-to-case citation network, to transition through a loading phase. During this loading phase, the largest weakly connected component of the graph generally lacked any meaningful clustering. However, this sparsely connected graph would soon give way, and by the early 1820’s, the largest weakly connected component displayed detectable structure.”
We also explore this network in our 2010 paper — Michael Bommarito, Daniel Martin Katz, Jonathan Zelner & James Fowler, Distance Measures for Dynamic Citation Networks 389 Physica A 4201 (2010) < SSRN > < arXiv >
It has my great pleasure to serve as a guest instructor in the Stanford Legal Informatics class! Thanks to Roland Vogl + Michael Genesereth for allowing me to connect with the students in this course.
It was my great pleasure to give the opening Keynote Address at IE LawX 2017. I would like to extend my thanks to IE Law School, Dean Javier de Cendra and to all of the team who put on a fantastic event on #LegalTech #LegalInnovation #LegalAI!
Here is Version 2.01 of the Law on the Market Paper —
From the Abstract: What happens when the Supreme Court of the United States decides a case impacting one or more publicly-traded firms? While many have observed anecdotal evidence linking decisions or oral arguments to abnormal stock returns, few have rigorously or systematically investigated the behavior of equities around Supreme Court actions. In this research, we present the first comprehensive, longitudinal study on the topic, spanning over 15 years and hundreds of cases and firms. Using both intra- and interday data around decisions and oral arguments, we evaluate the frequency and magnitude of statistically-significant abnormal return events after Supreme Court action. On a per-term basis, we find 5.3 cases and 7.8 stocks that exhibit abnormal returns after decision. In total, across the cases we examined, we find 79 out of the 211 cases (37%) exhibit an average abnormal return of 4.4% over a two-session window with an average |t|-statistic of 2.9. Finally, we observe that abnormal returns following Supreme Court decisions materialize over the span of hours and days, not minutes, yielding strong implications for market efficiency in this context. While we cannot causally separate substantive legal impact from mere revision of beliefs, we do find strong evidence that there is indeed a “law on the market” effect as measured by the frequency of abnormal return events, and that these abnormal returns are not immediately incorporated into prices.