Market value,R&D,and patents

A significant relationship is found between the market value of the firm and its ‘intangible’ capital, proxied by past R&D expenditures and the number of patents, based on a time-series cross-section analysis of data for large U.S. firms.     

Patents and R&D at the firm level: A first report

The U.S. Patent Office has recently computerized its data base. Thus an easily accessible rather direct indicator of the inventive output of firms is now available. We examine the sense in which the patent measure is a ‘good’ indicator of inventive activity by relating it to the R&D expenditures of a cross-section of 121 firms over an 8 year period.     

Characteristics of demand for pharmaceutical products: an examination of four cephalosporins

We model demand for four cephalosporins and compute own- and cross-price elasticities between branded and generic versions of the four drugs. We model demand as a multistage budgeting problem, and we argue that such a model is appropriate to the multistage nature of the purchase of pharmaceutical products, in particular the prescribing and dispensing stages. We find quite high elasticities between generic substitutes and also significant elasticities between some therapeutic substitutes.     

The inconsistency of common scale estimators when output prices are unobserved and endogenous

This paper explores the inconsistency of common scale estimators when output is proxied by deflated sales, based on a common output deflator across firms. The problem arises when firms operate in an imperfectly competitive environment and prices differ between them. In particular, we show that this problem reveals itself as a downward bias in the scale estimates obtained from production function regressions, under a variety of assumptions about the pattern of technology, demand and factor price shocks. The result also holds for scale estimates obtained from cost functions. The analysis is carried one step further by adding a model of product demand. Within this augmented model we examine the probability limit of the scale estimate obtained from an ordinary production function regression. This analysis reveals that the OLS estimate will be biased towards a value below one, and how this bias is affected by the magnitude of the parameters and the amount of variation in the various shocks. We have included an empirical section which illustrates the issues. The empirical analysis presents a tentative approach to solve the problem discussed in the theoretical part of this paper.     

Empirical Patterns of Firm Growth and R&D Investment: a Quality Ladder Model Interpretation

We present a partial equilibrium model of endogenous firm growth with R&D investment and stochastic innovation as the engines of growth, drawing on the quality ladder models in the macro growth literature, and the literature on patent races and the discrete choice models of product differentiation. The model fits a number of empirical patterns well, including: (i) a skewed size distribution of firms with persistent differences in firm sizes, (ii) firm growth independent of firm size, as stated in the so-called Gibrat's law, and (iii) R&D investment proportional to sales.