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What isComputational Legal Studies?
Daniel Martin KatzMichigan State University
College of Law
What is Computational Legal Studies?
What is Computational
Legal Studies?
Computational Legal Studies
is
Sociophysics
Natural Language Processing
Machine Learning
Network Science
Statistical Methods
Out of Equilibrium Models
Non Linearity
Scaling
Diffusion
Social Epidemiology
Information Theory
New Kind of Science
Computational Game Theory
Web Scrapping
Information Visualization
What is Computational
Legal Studies?
Computational Legal Studies
Offers
A Set of Tools
that allow us
to perhaps better understand
‘Law’ in a modern society
Taxonomy of Approaches
Data Analysis
FormalModels
Computational Legal Studies
Data Analysis
FormalModels
Computational Legal Studies
Data Analysis
This is the Era of “Big Data”
Decreasing Data Storage Costs
Increasing Computing Power
Fundamentally Altering the Scope of Scientific Inquiry
Highlighting the Data Deluge
2008 2009 2010
The Case for a Computational Approach
Legal Systems Output large amounts of Information
Need Methods that Scale to the Size and Scope of this Body of Information
Data Analysis
statisticalmodels
and methods
network analytic methods
text as
data
other related
approaches
What is Computational Legal Studies?
Computational Legal Studies
is
quantitativelegal prediction
do i have a case?
how do lawyers generate this assessment?
can it be automated?
Mental Models vs
Aggregated Data
Weather Prediction
Tide Prediction
vs.
lots of factors matter
Inputs / Data Quality
Time Scales Matter
inherent system variability matters
‘complexity’ matters
Some Potential Inputs
what is the relevant information contained
therein?
text, citations, votes, etc.
other metadata
what form might the outputs take?
standard client memo
+
statistical portrait of 10,000 ‘similar’ cases
the caveat
your mileage may vary
but a statistical portrait
would be useful
to gut check a mental model
other big
implications ...
the market for legal services
the market for legal education
‘thinking like a lawyer’?
in the age of big data ...
What is Computational Legal Studies?
Data Analysis
FormalModels
FormalModels
Formal Models
computationalgame
theory
network models
AgentBased
Modeling
Why Generate Formal Models?
Formal Models v.
Data
The Evaluation of Counterfactuals
The Evaluation of Alternative
‘States of the world’
Cannot not be Exclusively Data Driven
A Few Examples ...
Theoretical Models and Computational Simulations
schelling’s segregation model
Axelrod’s Evolution of Cooperation model
An Entire Course on Computational Formal Models
18 Classes and more than 1000 slides!
ICPSRSummer Methods Program
computationalgame
theory
network models
AgentBased
Modeling
What is Computational Legal Studies?
Data Analysis
FormalModels
statisticalmodels
and methods
network analyticmethods
text as
data
and more ...
Now Some Selected
Applications
Project #1:United States Code
The United States Code
Compiled Version of Federal Statutory Law
Drawn from the Statutes at Large
Does not Include Admin Regulations
The United States Code
These are the 50 titles in the Code
A Perspective on the Scope of Law in a Modern Society
How Large is the United States Code?
How Complex is the United States Code?
How has its Scope Changed Over Time?
Are Changes in Code Coupled with Changes in the Scope of the Administrative State?
How Large is the United States Code?
How Large is the United States Code?
How Large is the United States Code?
How Large is the United States Code?
~Title 29 - Labor
How Large is the United States Code?
This is the United States Code
Computational Approach to Measurement of Complexity
Measure that Representation in a Manner that is Qualitatively Justified
Provide a Mathematical Representation of the Object
The US Code as a Mathematical Object
Hierarchical Structure
Title 26
Subtitle A
Chapter 1
Subchapter F
Part I
Section 501
Subsection (c)
Paragraph (3)http://arxiv.org/abs/1003.4146
Citation Network
Example: Tax Evasion
Title 26 - Tax
Cites
Title 18 - Crimes &
Criminal Procedure
The US Code as a Mathematical Object
http://computationallegalstudies.com
LinguisticContent
United States Code Features
24 Million Words
The US Code as a Mathematical Object
Published in Physica A (October 2010)
The US Code as a Mathematical Object
How Complex is U.S. Code?
Ongoing Project --
Daniel Katz & Michael Bommarito
“Measuring the Complexity of the United States Code”
The Complexity of Knowledge Acquisition
3 Factors Influence Complexity ofExecuting a KA Protocol
Structure Language Dependence
Project #2:
Network Analysis of the Federal Judiciary
the Federal Judicial Heirarchy
United States Supreme Court
Federal Court of Appeals
Federal District Court
What is the Social Topology of the American Federal Judiciary?
... And How Can We Measure it?
Collected Nearly 19,000 Law Clerk ‘Events’
1995 - 2005 For All Article III Judges
Relying Upon Data From Staff Directories
Network Analysis of the Federal Judiciary
The Core Claim
In the Aggregate ...
Law Clerk Movements Reveal
Between Judicial Actors
Social or Professional Relationships
Network Analysis of the Federal Judiciary
Judge E
Justice ZJustice Y
Judge C
Judge D
Judge BJudge A
Network Analysis of the Federal Judiciary
Network Analysis of the Federal Judiciary
Daniel Katz & Derek Stafford
(2010)
Project #3:
Exploring the Path of Precedent?
The Legal Genome Project and the analysis of Judicial Citations
The United States Reports
Nodes = Cases Decided by the Supreme Court
Directed Edges = Citations between Cases
United States Supreme CourtCase to Case Citation Network
Case to Case Citation Networkof the
United States Supreme Court
Dickerson v. U.S.530 U.S. 428 (2000)
Miranda v. Arizona384 U.S. 436 (1966)
Oregon v. Elstad530 U.S. 428 (2000)
Exploring the Path of Precedent?
Dynamic Visualization of the Early Supreme Court Citation Network
Cases Decided by the Supreme Court
Citations in the Current Year
Citations from prior years
http://computationallegalstudies.com/2010/02/11/the-development-of-structure-in-
the-citation-network-of-the-united-states-supreme-court-now-in-hd/
PLAY MOVIE!
Beijing
Distance Measures for Dynamic Citation Networks
Growth Rules For Citation Networks
Dynamic Directed Acyclic Graphs
Dynamic Directed Acyclic Graphs
Examples: Academic Articles
Dynamic Directed Acyclic Graphs
Examples: Academic Articles
Judicial Citations
Dynamic Directed Acyclic Graphs
Examples:
Academic Articles
Judicial Citations
Patent Citations
Network Dynamics:
The Early Jurisprudence of the United States Supreme Court
Cases Decided by the Supreme Court
Citations in the Current Year
Citations from prior years
A Formalization of D-DAG’s
Six Degrees of Marbury v. Madison
A Formalization of D-DAG’s
Basic Idea of Sink Based Distance Measure
The Simplest Non-Trivial Distance Measure
Flexible Framework For More Detailed Specifications
Distance Measure <- ->
Dendrogram
Potential Application to Patent Citations?
Sternitzke, Bartkowski & Schramm (2008)
Potential Application to Patent Citations?
http://www.eecs.umich.edu/cse/dm_11_video/erdi.mp4
http://people.kzoo.edu/~perdi/Talk By Péter Érdi
Network Analysis of Patent Citations
http://ssrn.com/author=627779
http://arxiv.org/abs/0909.1819available at:
AdditionalMaterialsAvailableOnline!
@computational
Thank You For Your Attention!
