David B. Audretsch

Innovation in Cities: Science-Based Diversity, Specialization and Localized Competition

Whether diversity or specialization of economic activity better promotes technological change and subsequent economic growth has been the subject of a heated debate in the economics literature. The purpose of this paper is to consider the effect of the composition of economic activity on innovation. We test whether the specialization of economic activity within a narrow concentrated set of economic activities is more conducive to knowledge spillovers or if diversity, by bringing together complementary activities, better promotes innovation. The evidence provides considerable support for the diversity thesis but little support for the specialization thesis.

Company-Scientist Locational Links: The Case of Biotechnology

In recent years, the significance of geography among firms has declined due to the introduction of electronic methods of communication. However, with the increasing presence of the biotechnology industry, with its affiliated university-based scientists, the issue of geography is proposed as a significant issue for consideration. Most notably, researchers cite that the role of the scientist within the firm impacts the geographic proximity between the firm and the scientist. The types of links between scientists and firms are examined, drawing on a database of biotech firms that have issued IPOs. The data analyses indicate that firm proximity is often influenced not only by the scientists role in the firm, but also by his or her status in the scientific community and by his or her age. Although past studies have cited the relationship between informal knowledge spillovers and proximity, the current research suggests that geographic proximity plays a less significant role when knowledge is transmitted through formal ties between scientists and corporations. Areas of future research are identified, including the impact of factors such as the proximity of other firm locations and research institutions, and how the role of geography differs between regions. (AKP)

Innovation, Market Structure, and Firm Size

The hypothesis that the relative innovative advantage between large and small firms is determined by market concentration, the extent of entry barriers, the composition of firm size within the industry, and the overall importance of innovation activity is tested. The authors find that large firms tend to have the relative innovative advantage in industries that are capital intensive, concentrated, highly unionized, and produce a differentiated good. The small firms tend to have the relative advantage in industries that are highly innovative, utilize a large component of skilled labor, and tend to be composed of a relatively high proportion of large firms. Copyright 1987 by MIT Press.

New Firm Survival: New Results Using a Hazard Function

A limitation of Audretschs 1991 study of new-firm survival was the level of aggregation to industries. This precluded linking establishment-specific characteristics, such as organizational structure and size, to post-entry performance. The purpose of this paper is to relate the post-entry performance of individual establishments not only to their technological and market structure environments, but also to establishment-specific characteristics. We do this by estimating a hazard duration function for more than 12,000 individual establishments in U.S. manufacturing started in 1976 by tracking their subsequent performance over a ten-year period. We conclude that establishment-specific characteristics, which Audretsch was not able to capture in his earlier study, play an important role in shaping the exposure to risk confronting new establishments. Copyright 1995 by MIT Press.

R&D Spillovers and Recipient Firm Size

The findings in this paper provide some insight into how small firms are able to innovate. Using a production function approach to relate knowledge generating inputs to innovative output, the empirical results suggest that small firms are the recipients of R&D spillovers from knowledge generated in the R&D centers of their larger counterparts and in universities. Such R&D spillovers are apparently more decisive in promoting the innovative activity of small firms than of large corporations. Copyright 1994 by MIT Press.

Knowledge spillovers and the geography of innovation

This chapter focuses on the geographic dimensions of knowledge spillovers. The starting point comes from the economics of innovation and technological change. This tradition focused on the innovation production function however it was aspatial or insensitive to issues involving location and geography. However, empirical results hinted that knowledge production had a spatial dimension. Armed with a new theoretical understanding about the role and significance of knowledge spillovers and the manner in which they are localized, scholars began to estimate the knowledge production function with a spatial dimension. Location and geographic space have become key factors in explaining the determinants of innovation and technological change. The chapter also identifies new insights that have sought to penetrate the black box of geographic space by addressing a limitation inherent in the model of the knowledge production. These insights come from a rich tradition of analyzing the role of both localization and urbanization economies, by extending the focus to the organization of economic activity within a spatial dimension and examine how different organizational aspects influence economic performance. While the endogenous growth theory emphasizes the importance of investments in research and development and human capital, a research agenda needs to be mapped out identifying the role that investments in spillover conduits can make in generating economic growth. It may be that a mapping of the process by which new knowledge is created, externalized and commercialized, hold the key to providing the microeconomic linkages to endogenous macroeconomic growth.

New-Firm Survival and the Technological Regime

The survival rates of over 11,000 firms established in 1976 are compared across manufacturing industries. The variation in ten-year survival rates across industries is hypothesized to be the result of differences in the underlying technological regime and industry-specific characteristics, especially the extent of scale economies and capital intensity. Based on 295 four-digit standard industrial classification industries, new-firm survival is found to be promoted by the extent of small-firm innovative activity. The existence of substantial scale economies and a high capital-labor ratio tends to lower the likelihood of firm survival. However, these results apparently vary considerably with the time interval considered. Market concentration is found to promote short-run survival, while it has no impact on long-run survival. Copyright 1991 by MIT Press.

Real Effects of Academic Research: Comment

Compares Jaffes work on the use of patents as a measure of the spillover of university research with the work of Acs and Audretsch in which innovation activity is measured by number of innovations. Jaffes work, which modified the knowledge production function proposed by Griliches, showed a positive relationship between corporate patent activity and commercial spillovers from university research. This research approach was criticized by many. In 1987, Acs and Audretsch proposed measuring innovative activity by the number of innovations recorded in 1982 by the U.S. Small Business Administration. It was believed that using number of innovations, using those provided a more direct measure than Jaffes work because inventions that were not patented but were introduced into the market were counted and inventions that were patented but never introduced were not counted. This analysis seeks to compare the two works. Jaffe used a pool of data that spanned an eight-year period while Acs and Audretsch considered a single year, 1982. It is shown that using a single year sample in Jaffes model does not greatly alter the results, which means that both private corporate expenditures on R&D and university expenditures on research both positively and significantly influence patent activity. The impact of university spillovers is greater on innovations than patents using Jaffes model. By directly substituting the innovation measure for the patent measure, this research approach shows further support for Jaffes findings and arguments. (SRD)

Innovative Clusters and the Industry Life Cycle

The purpose of this paper is to link the propensity for innovative activity to spatially cluster to the stage of the industry life cycle. The theory of knowledge spillovers, based on the knowledge production function for innovative activity, suggests that geographic proximity matters the most where tacit knowledge plays an important role in the generation of innovative activity. According to the emerging literature of the industry life cycle, tacit knowledge plays the most important role during the early stages of the industry life cycle. Based on a data base that identifies innovative activity for individual states and specific industries for the United States, the empirical evidence suggests that the propensity for innovative activity is shaped by the stage of the industry life cycle. While the generation of new economic knowledge tends to result in a greater propensity for innovative activity to cluster during the early stages of the industry life cycle, innovative activity tends to be more highly dispersed during the mature and declining stages of the life cycle, particularly after controlling for the extent to which the location of production is geographically concentrated. This may suggest that the positive agglomeration effects during the early stages of the industry life cycle become replaced by congestion effects during the latter stages of the industry life cycle.

Does Entry Size Matter? The Impact of the Life Cycle and Technology on Firm Survival

A wave of empirical studies has recently emerged showing that smaller-scale entry is confronted with a lower likelihood of survival than their larger counterparts. The purpose of this paper is to examine whether the relationship between size of a firm when entering an industry and the likelihood of survival holds under different technological conditions and across the different stages of the industry life cycle. The empirical evidence suggests that the relationship between firm size and the likelihood of survival is shaped by technology and the stage of the industry life cycle. While the likelihood of survival confronting small entrants is generally less than that confronting their larger counterparts, the relationship does not hold for mature stages of the product life cycle, or in technologically intensive products. In mature industries that are still technologically intensive, entry may be less about radical innovation and possibly more about filling strategic niches, thus negating the impact of entry size on the likelihood of survival. Copyright 2001 by Blackwell Publishing Ltd