Marijn Koolen

Legal Structures — A Digging Into Data Project


Analyzing Reference Networks of the World's Civil Codes and Constitutions

This project takes a radically novel approach to the problem of measuring and visualizing differences among legal systems: it focuses on machine coding of internal references in codes and laws.

Internal referencing is an inherent characteristic of codes. Already the Code of Hammurabi, almost 3800 years ago, was structured as a numbered list of laws with at least one cross-reference.

The intuition behind this approach is that fundamental differences among legal systems manifest themselves in the structure of the texts and can be detected, parameterized, and visualized using computerized algorithms. For instance, the French Civil Code—based on a deductive ideal of legal thought—has fewer internal references than the hundred-year younger German Civil Code—influenced by the idea that law finds its legitimacy in the history of a country rather than on natural principles and hence is less organically structured. We use this procedure to analyze the world’s codes and constitutions.


  • Giuseppe Dari-Mattiacci — Professor of Law and Economics, University of Amsterdam
  • Adam Badawi — Professor of Law, Washington University School of Law, St Louis
  • Rens Bod — Professor of Computational and Digital Humanities, University of Amsterdam
  • Marijn Koolen — Assistant Professor of Digital Humanities, University of Amsterdam
  • Bart Karstens — Post doc, University of Amsterdam

On the civil codes

  • James Daily — Research Technologist, Washington University School of Law, St Louis

On the constitutions

  • Tom Ginsburg — Leo Spitz Professor of International Law and Professor of Political Science at the University of Chicago


We thank the Comparative Constitutions Project and the Constitute Project for making their many data sets available.

We gratefully acknowledge the Digging Into Data Challenge 2013 for generously funding our project.