The TRIPS Agreement, which specifies minimum levels of intellectual property protection for countries in the WTO, has increased levels of patent protection around the world. Using variation across countries in the timing of patent laws and the severity of disease, we test the hypothesis that increased patent protection results in greater drug development effort. We find that patent protection in wealthy countries is associated with increases in R&D effort. However, the introduction of patents in developing countries has not been followed by greater R&D investment in the diseases that are most prevalent there.

In this study, we use data for 1981 through 1994 on a large sample of U.S. companies to examine the persistence of incremental industry, corporate-parent, and business-specific effects on profitability. Our results indicate that the incremental effects of industry on profitability persist longer than the incremental effects of the corporate parent and of the specific business. Changes in industry structure have a more persistent impact on profitability than do changes in firm structure.