In this paper I evaluate the contribution of R&D investments to productivity growth. The basis for the analysis are the free entry condition and the fact that most R&D innovations are embodied. Free entry yields a relationship between the resources devoted to R&D and the growth rate of...

A well-developed theoretical literature -- dating back at least to Nordhaus (1969) -- has analyzed optimal patent policy design. We re-present the core trade-off of the Nordhaus model and highlight an empirical question which emerges from the Nordhaus framework as a key input into optimal patent...

The empirical analysis in "International R&D Spillovers" (Coe and Helpman, 1995) is first revisited by applying modern panel cointegration estimation techniques to an expanded data set that we have constructed for the purpose of this study. The new estimates confirm the key results reported in...

The U.S. business sector has under-invested relative to Tobin's Q since the early 2000's. We argue that declining competition is partly responsible for this phenomenon. We use a combination of natural experiments and instrumental variables to establish a causal relationship between competition...

In this paper, we design two laboratory experiments to analyze the causal effects of competition on step-by-step innovation. Innovations result from costly R&D investments and move technology up one step. Competition is inversely measured by the ex post rents for firms that operate at the same...

(1) Whatever happened to the cyclical effect? Skeptics were justified on the basis of data through the end of 1999 in their claim that part of the post-1995 productivity growth revival reflected the normal cyclical correlation between productivity and output growth. In contrast data through...