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...

This paper studies how patent rights and price regulation affect how fast new drugs are launched in different countries, using newly constructed data on launches of 642 new drugs in 76 countries for the period 1983-2002, and information on the duration and content of patent and price control...

We formulate a variable cost function model in which certain inputs are treated as quasi-fixed, and develop a simple statistical test of whether optimization occurs for the quasi-fixed inputs. It is shown how to retrieve characteristics of the long-run cost function from the variable cost...

We show that economic incentives affect the number and commercial value of inventions generated in universities. Using panel data for 102 U.S. universities during the period 1991-1999, we find that universities which give higher royalty shares to academic scientists generate more inventions and...

This paper explores the economic factors which determine the variation of research effort across firms. The intra-industry coefficient of variation of research intensity is much larger than those of traditional factors. We show that this important fact is consistent with the theoretical argument...

This paper presents quantitative estimates of the private value of property rights conferred by patent protection for different technology fields and countries of ownership. The measures are derived from parametric estimation of a model of patent renewal, using a new data set on patent renewals...

This paper develops an econometric model of the effects of R&D effort on the magnitude and characteristics of technical change in the Bell system. We estimate simultaneously a vintage capital production function, embodying several distinct types of capital, and various factor demand functions...

We model early expectations about the value and technological importance ('quality') of a patented innovation as a latent variable common to a set of four indicators: the number of patent claims, forward citations, backward citations and family size. The model is estimated for four technology...

The objectives of this preliminary study are threefold. The first is to analyze empirically the production structure of the Bell System at the aggregate level. Particular attention is focused on the pattern of substitution among the factor inputs and the degree to which the aggregate production...

This paper proposes a framework which integrates convex costs of adjustment and expectations formation in the determination of investment decisions in R&D at the firm level. The model is based on cost minimization subject to the firm's expectations of the stream of output and the price of R&D,...