This article focuses on the effects of double-counting and expensing on the measured returns to R&D. The contribution of research and development (R&D) to economic growth has been measured in two general ways. The first is to compute total factor productivity in a growth accounting framework and to attribute this growth to R&D. The prevailing view is that, in the presence of double-counting, the measured contribution of R&D represents the return above and beyond the normal remuneration to traditional capital. Author demonstrate that this excess returns interpretation (ERI) is essentially correct in the growth accounting framework and that the resulting bias in the measured contribution of R&D to growth is large. In postwar U.S. manufacturing the measured residual is biased downward by as much as 30%. The expensing bias is downward and reinforces the excess returns bias in this case, and the total bias is large. In both the growth accounting and econometric contexts, the magnitude of the biases may vary across samples and over time. There is simply no substitute for properly measured variables.

This paper empirically explores the dynamic interactions among research and development, capital investment, and the stock market performance of 191 firms in science-based industries during the period 1973-81. Using a framework based on dynamic factor analysis, we test asymmetric specifications of the dynamics between R & D and investment. The data indicate that R & D Granger-causes investment but that investment does not Granger-cause R & D. We discuss interpretations of this causal ordering, characterize the stylized facts of the movements over time of R & D and investment, and measure the stock market valuation of these movements.

This paper empirically explores the dynamic interactions among research and development, capital investment, and the stock market performance of 191 firms in science-based industries during the period 1973-81. Using a framework based on dynamic factor analysis, we test asymmetric specifications of the dynamics between R & D and investment. The data indicate that R & D Granger-causes investment but that investment does not Granger-cause R & D. We discuss interpretations of this causal ordering, characterize the stylized facts of the movements over time of R & D and investment, and measure the stock market valuation of these movements.

Abstract Critics claim that patent screening is ineffective, granting low-quality patents that impose unnecessary social costs. We develop an integrated framework, involving patent office examination, fees, and endogenous validity challenges in the courts, to study patent screening both theoretically and quantitatively. In our model, some inventions require the patent incentive while others do not, and asymmetric information creates a need for screening. We show that the endogeneity of challenges implies that courts, even if perfect, cannot solve the screening problem. Simulations of the model, calibrated on U.S. data, indicate that screening is highly imperfect, with almost half of all patents issued on inventions that do not require the patent incentive. While we find that the current patent system generates positive social value, intensifying examination would yield large welfare gains. The social value of the patent system would also be larger if complemented by antitrust limits on licensing.

Abstract Cumulative innovation is central to economic growth. Do patent rights facilitate or impede follow-on innovation? We study the causal effect of removing patent rights by court invalidation on subsequent research related to the focal patent, as measured by later citations. We exploit random allocation of judges at the U.S. Court of Appeals for the Federal Circuit to control for endogeneity of patent invalidation. Patent invalidation leads to a 50% increase in citations to the focal patent, on average, but the impact is heterogeneous and depends on characteristics of the bargaining environment. Patent rights block downstream innovation in computers, electronics, and medical instruments, but not in drugs, chemicals, or mechanical technologies. Moreover, the effect is entirely driven by invalidation of patents owned by large patentees that triggers more follow-on innovation by small firms.

Abstract We study the effects of the Medicines Patent Pool (MPP)—an institution that pools patents across geographical markets—on the licensing and adoption of life-saving drugs in low- and middle-income countries. We show the presence of an immediate and large increase in licensing when a patent is included in the MPP. We also show evidence that the pool increases actual entry and volume of sales, but these impacts are much smaller than on licensing, which is due to the geographic bundling of licenses. The paper highlights the potential of pools in promoting diffusion of biomedical innovation in developing countries.

Using new data on citations to university patents and scientific publications, we study how geography affects university knowledge spillovers. Citations to patents decline sharply with distance and are strongly constrained by state borders. The effect of distance on citations to scientific publications is less sharp, and the state border effect on publications is significant only for lower-quality public universities. We show that the state border effect is heterogeneous and strongly influenced by university and state characteristics and policies. It is larger for universities that are public and that have strong local development policies, and in states with strong noncompete labor laws, greater reliance on in-state educated scientists, and lower rates of interstate scientific labor mobility. We confirm the impact of noncompete statutes by studying a policy reform in Michigan.

Analysis of the timing of launches of 642 new drugs in 76 countries during 1983–2002 shows that patent and price regulation regimes strongly affect how quickly new drugs become commercially available in different countries. Price regulation delays launch, while longer and more extensive patent rights accelerate it. Health policy institutions and economic and demographic factors that make markets more profitable also speed up diffusion. The estimated effects are generally robust to controlling for endogeneity of policy regimes with country fixed effects and instrumental variables. The results highlight the important role of policy choices in driving the diffusion of new innovations.

The impact of R&D on growth through spillovers has been a major topic of economic research over the last thirty years. A central problem in the literature is that firm performance is affected by two countervailing “spillovers” : a positive effect from technology (knowledge) spillovers and a negative business stealing effects from product market rivals. We develop a general framework incorporating these two types of spillovers and implement this model using measures of a firm's position in technology space and productmarket space. Using panel data on U.S. firms, we show that technology spillovers quantitatively dominate, so that the gross social returns to R&D are at least twice as high as the private returns. We identify the causal effect of R&D spillovers by using changes in federal and state tax incentives for R&D. We also find that smaller firms generate lower social returns to R&D because they operate more in technological niches. Finally, we detail the desirable properties of an ideal spillover measure and how existing approaches, including our new Mahalanobis measure, compare to these criteria.