A puzzling feature of many medical innovations is that they simultaneously appear to reduce unit costs and increase total costs. We consider this phenomenon by examining the diffusion of percutaneous transluminal coronary angioplasty (PTCA) -- a treatment for coronary artery disease -- over the...

The emergence of novelty, especially of new categories of people and organizations, is undertheorized in the social sciences. Some social worlds are more hospitable to novel introductions or exogenous perturbations than others. Explaining this relative "poisedness" is essential to understanding...