Social Network Analysis 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 appear to define an important reference group in the diffusion process, and social network effects dominate economic and political variables. In addition, the de facto separation of powers in the enactment of new state legislation appears 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 Republican or Democratic, state courts were more inclined to adopt the strict liability rule.