We extend the basic Schumpeterian endogenous growth model by allowing incumbents to undertake innovations to improve their products, while entrants engage in more "radical" innovations to replace incumbents. Our model provides a tractable framework for the analysis of growth driven by both entry...

Technological innovation is not a blessing for all firms, or for investors holding the market. In the late 20th century US, individual firms' stock returns correlate positively with their own productivity growth, yet the market return correlates negatively with aggregate productivity growth,...

Preventives are sold ex ante, before disease status is realized, while treatments are sold ex post. Even if the mean of the ex ante distribution of consumer values is the same as that ex post, the shape of the distributions may differ, generating a difference between the surplus each product can...

We provide a model and empirical tests showing how an active acquisition market affects firm incentives to innovate and conduct R&D. Our model shows that small firms optimally may decide to innovate more when they can sell out to larger firms. Large firms may find it disadvantageous to engage in...

We argue that in pharmaceutical markets, variation in the arrival time of consumer heterogeneity creates differences between a producer's ability to extract consumer surplus with preventives and treatments, potentially distorting R&D decisions. If consumers vary only in disease risk, revenue...

The local academic science base plays a dominant role in determining where and when biotechnology is adopted by existing firms or -- much more frequently -- exploited by new entrants in the U.S. In Japan this new dominant technology has almost exclusively been introduced through organizational...

In a simple representative consumer model, vaccines and drug treatments yield the same revenue for a pharmaceutical manufacturer, implying that the firm would have the same incentive to develop either ceteris paribus. We provide more realistic models in which the revenue equivalence breaks down...

We study the effects of generic entry on prices and utilization using both event study models that exploit the differential timing of generic entry across drug molecules and cast studies. Our analysis examines drugs treating hypertension, high blood pressure, type 2 diabetes, and depression...