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...

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...

This paper asks the question: Can we see evidence of General Purpose Technologies in patent data? Using data on three million US patents granted between 1967 and 1999, and their citations received between 1975 and 2002, we construct a number of measures of GPTs, including generality, number of...

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...

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...

The israeli high tech sector is widely regarded as a hotbed of cutting-edge technologies, and as the growth engine of the israeli economy in the nineties and beyond. In this paper we present a close-up portrait of innovation in Israel for the past 30 years, with the aid of highly detailed patent...

We push the span of hedonic price calculations for automobiles backwards towards the industry's birth. Most of the real change that occurred between 1906 and 1982 occurred between 1906 and 1940. During these years, hedonic prices fell at an average annual rate of 5%. The pace was brisker still...

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...

This paper seeks to analyze the nature of the terrorist threat following 9/11, and to explore the implications for defense R&D policy. First it reviews the defining trends of defense R&D since the cold war, and brings in pertinent empirical evidence: The US accumulated during the 1990s a defense...

The steam engine is widely regarded as the icon of the Industrial Revolution and a prime example of a 'General Purpose Technology,' and yet its contribution to growth is far from transparent. This paper examines the role that a particular innovative design in steam power, the Corliss engine,...