Legal Precedents, Judicial Discretion, and the Diffusion of the Strict Liability Rule for Manufacturing Defects, 1963-87

This article reports the results of a study that uses social network analysis to compare the persuasiveness of legal precedents in the diffusion of the strict liability rule for manufacturing defects. This new study tests which legal precedents were most influential and also whether certain state judicial variables influenced the diffusion process. The results are striking. The federal circuit regions appeared to define an important reference group in the diffusion process and social network effects dominated economic and political variables. In addition, the de facto separation of powers in the enactment of new state legislation appeared to influence courts’ propensities to adopt the strict liability rule. When the executive and legislative branches were controlled by the same political party – regardless of whether it was the Republican or Democratic Party – state courts were more inclined to adopt the strict liability rule. This last result contradicts an economic hypothesis that predicts courts should be less inclined to exercise discretion when the de facto separation of powers between the executive and legislative branches is narrower