Estimating the Authority of Case Law Using Markov Machinery

• In Event: Methods and Measures

Abstract

How does the authority of case law evolve over time? On the Dworkinian legal formalist view, each link in the "chain" of legal precedent increases in authority monotonically, but on the Holmesian legal realist view, each case’s authority is proportional to its ability to predict future legal outcomes. In this paper, I show how modeling the network of U.S. Supreme Court case law not as a chain novel (a la Dworkin) but instead as a Markov chain (a la Holmes, or so I argue) unlocks an intuitive measure of case authority that outperforms the existing approach (Fowler et al. 2007; Fowler and Jeon 2008) in a variety of validation tasks. I then demonstrate how the authority scores produced using the Markov machinery empower the analysis of two important normative questions: (1) the ideological basis of lasting precedential authority and (2) the causal effect of the Supreme Court’s citation choices on lower court compliance. I present evidence suggesting that ideologically homogenous coalitions are no more likely than diverse ones to leave a lasting imprint on the law, but that the Supreme Court as a whole enjoys a previously unrecognized power to shape the law through its resuscitation of decisions from the past.

Author

• Matthew Dahl, Yale Law School