The main goal of this paper is to put forward a methodology for the measurement of product innovations using a value metric, i.e., equating the "magnitude" of innovations with the welfare gains that they generate. This research design is applied to the case of Computed Tomography (CT) Scanners,...

The goal of this paper is to address the problem of 'product innovations' (i.e. new goods. increased variety, and quality change) in the construction of price indices and, by extension, in the measurement of economic performance. The premise is that a great deal of technical progress takes the...

Recent research on financial market valuation of the knowledge assets of publicly traded firms is surveyed. The motivation for using a market value equation to price knowledge assets is discussed and the theory behind this equation is briefly presented. Then the empirical literature that relates...

The contribution made by innovation and new technologies to economic growth and welfare is largely determined by the rate and manner by which innovations diffuse throughout the relevant population, but this topic has been a somewhat neglected one in the economics of innovation. This chapter,...

The main goal of this paper is to develop an empirical framework for evaluating the patient welfare benefits arising from pharmaceutical innovation. Extending previous studies of the welfare benefits from innovation (Trajtenberg, 1990; Hausman, 1996), this paper unpacks the separate choices made by...

This paper studies the consequences of physician authority on pharmaceutical prescribing. Physicians engage in a costly process of particular conditions and characteristics. The relative efficiency of this matching process results from the diagnostic skill of the physician along with the...

History and theory alike suggest that General Purpose Technologies (GPT's), such as the steam engine or electricity, may play a key role in economic growth. In a previous paper (Helpman and Trajtenberg, 1994) we incorporated this notion into a Grossman-Helpman growth model, and explored the...

This paper evaluates the sources of transitory market power in the market for personal computers (PCs) during the late 1980's. Our analysis is motivated by the coexistence of low entry barriers into the PC industry and high rates of innovative investment by a small number of PC manufacturers. We...

We develop a model of growth driven by successive improvements in 'General Purpose Technologies' (GPT's), such as the steam engine, electricity, or micro-electronics. Each new generation of GPT's prompts investments in complementary inputs, and impacts the economy after enough such compatible...