Author ORCID Identifier

Sag 0000-0003-2381-1028

Jacobi 0000-0002-5200-5765

Document Type


Publication Date



Intellectual property, Supreme Court, Judicial ideology, Attitudinal model, Liberal-conservative scale


In this Article, we examine the effect of judicial ideology on IP case outcomes before the Supreme Court from 1954 to 2006. We find that ideology is a significant determinant of IP cases: the more conservative a justice is, the more likely he or she is to vote in favor of recognizing and enforcing rights to intellectual property. We also find evidence that the relationship is more complex than a purely ideological account would suggest; our results suggest that law matters too. We find that a number of factors that are specific to IP are also consequential. Additionally, we show that although ideology is highly predictive of IP outcomes, the size of this effect is nonetheless significantly lower than it is in cases involving prominent social issues, such as voting rights or the death penalty. We therefore conclude that although ideology is an important element in predicting IP decisions, there may nonetheless be real differences between the effect of ideology in social and economic cases.

Part I of the Article explains the basis for the broad attitudinal claim that case outcomes have ideological derivations. It then presents the theoretical basis for the competing claim that IP is immune to the general impact of ideology on judicial decisions. Part II provides an overview of some of the anecdotal evidence relied upon by exceptionalists and the attitudinalist response. We identify three central interrelated phenomena that scholars point to as evidence of IP’s exceptionalism: the unusual prevalence of unanimous opinions, surprising judicial coalitions, and judges voting against ideological type. Part II also considers and counters these claims from an attitudinalist perspective. We conduct our empirical analysis in Part III. This Part first offers some impressionistic evidence of IP exceptionalism by comparing judicial voting coalitions in IP cases to coalitions in Supreme Court decisions generally. We then apply regression analysis to test four hypotheses: (1) that ideology affects judicial decision-making; (2) that the effect of judicial ideology on outcomes differs between various types of IP claims; (3) that the effect of ideology differs between liberal and conservative justices; and (4) that the effect of ideology on IP cases differs from its effects in other cases. Part IV presents the implications of our analysis for IP in particular and for judicial scholarship in general, and considers potential extensions of our analysis.

First Page


Publication Title

California Law Review