Theory predicts intense price competition when firms cluster with rivals. Yet, strong evidence of clustering is found in previous empirical research. Researchers typically measure clustering by comparing observed location patterns to random assignment. The random assignment benchmark does not,...

Why do businesses such as fast-food restaurants, coffee shops, and hotels cluster? In the classic analysis of Hotelling, firms cluster to attract consumers who have travel costs. We present an alternative model where firms cluster because one firm is free riding on another firm's information...

U.S. federal and state governments rarely regulate healthcare price levels, but do regulate price changes for pharmaceuticals, hospitals, and health insurance. Previous research showed that limiting price increases can raise launch prices and reduce both profit and social welfare, assuming...

In 2004 an Institute of Medicine report warned of vaccine shortages, raising concerns about disease outbreaks. More than a decade later, we looked for progress in reducing vaccine shortages. We analyzed data on vaccine sales and shortages reported by practitioners and patients to the Food and...

Drug development is costly so drug makers need accurate estimates of sales potential. However, sales forecasts are often unreliable. Our study is unique in combining a large sample of drug classes with data on entry order and promotional spending to estimate peak market share while controlling...

We estimate a model of drug demand and supply that incorporates insurance, advertising, and competition between branded and generic drugs within and across therapeutic classes. We use data on antiulcer drugs from 1991 to 2010. Our simulations show generics and ``me-too'' drugs each increased...

Beginning in the mid-2000s, the incidence of drug shortages rose, especially for generic injectable drugs such as anesthetics and chemotherapy treatments. We examine whether reimbursement changes contributed to the shortages, focusing on a reduction in Medicare Part B reimbursement to providers...