We study the betweenness centrality of fractal and non-fractal scale-free network models as well ... more We study the betweenness centrality of fractal and non-fractal scale-free network models as well as real networks. We show that the correlation between degree and betweenness centrality C of nodes is much weaker in fractal network models compared to non-fractal models. We also show that nodes of both fractal and non-fractal scale-free networks have power law betweenness centrality distribution P(C)
This paper analyses the propensity to withdraw European patent applications within a regional sam... more This paper analyses the propensity to withdraw European patent applications within a regional sample of Italian applicants. The procedure for obtaining a granted patent from the EPO is composed of a series of sequential and selective steps imposing additional costs to the applicants. Accordingly, we argue that early withdrawals - i.e. those occurring before the proper examination process begins - should be treated separately from late withdrawals. Our findings show the probability of an early withdrawal is higher for applicants with lower resources and competencies and rises with the number of backward citations added by EPO examiners to the original application. Late withdrawals, instead, are negatively affected by one factor only: the size of patent family, which approximates the sunk costs born by applicants in order to extend the geographical scope of patent protection. Such a limited explanation suggests that the interventions of EPO examiners are likely to play a significant r...
R&D, Innovation and Competitiveness in the European Chemical Industry, 2004
Chapter 7 THE NATURE AND THE EXTENT OF THE MARKET FOR TECHNOLOGYIN BIOPHARMACEUTICALS Ashish Aror... more Chapter 7 THE NATURE AND THE EXTENT OF THE MARKET FOR TECHNOLOGYIN BIOPHARMACEUTICALS Ashish Arora, Alfonso Gambardella, Fabio Pammolli and Massimo Riccaboni Carnegie Mellon University, St. Anna School of Advanced Studies, University of Florence-CERMand ...
In this paper, we investigate how underlying relevant technological conditions induce distinguish... more In this paper, we investigate how underlying relevant technological conditions induce distinguishable patterns of change in industry structure and evolution. A mapping is detected between the specific nature of problem decompositions and research techniques at the micro level of knowledge bases, and patterns of structural evolution at the macro level of the industry network. The graph-theoretic techniques we introduce map major technological discontinuities on changes observed at the level of dominant organization forms. They might have applications in other domains, whenever the identification of structural breaks and homological relationships between technological and industrial spaces are important issues. q F. Pammolli . 0048-7333r01r$ -see front matter q 2001 Elsevier Science B.V. All rights reserved.
The report examines the competitive position of the European pharmaceutical companies and industr... more The report examines the competitive position of the European pharmaceutical companies and industries, and compares them with the pharmaceutical companies and industries in other parts of the world, particularly the US. Over the last two decades, the industry has experienced some important structural changes, mainly driven by technological and institutional shocks that have affected all the stages of its value
An explosion of knowledge and a growing array of tools and technologies have transformed modern d... more An explosion of knowledge and a growing array of tools and technologies have transformed modern drug R&D, while its cost has risen by a sizable amount. At the same time, the unchecked increase in health care and prescription drug spending has spawned cost containment policies that are restricting the demand for drugs in all major markets. This Perspective explores the interplay between technological advances and regulatory policies and their likely impact on the dynamics of the pharmaceutical industry.
We test recent theory on the benefits of auctions and bargaining as alternative procurement mecha... more We test recent theory on the benefits of auctions and bargaining as alternative procurement mechanisms using data on the procurement of medical devices by Italian hospitals. Theory suggests that auctions perform well when cost control is the key concern, but are less effective at producing the optimal mix of quality and price for complex products where quality is difficult to
We refer to the framework developed by and to the notion of independent submarkets (Sutton 1998) ... more We refer to the framework developed by and to the notion of independent submarkets (Sutton 1998) to provide a simple candidate explanation for the shape of the firm growth distribution based on a model of proportional growth at the level of both the introduction of new products by firms and their size dynamics. We exploit the features of a unique longitudinal data set which covers the entire distribution of products and firms in the worldwide pharmaceutical industry to test the model at different levels of aggregation as well as at different time lags. Econometric investigations show that the model's predictions are in good agreement with empirical evidence. (JEL: L11, L65) (EPRIS Program) is gratefully acknowledged for financial support.
Complex systems can be characterized by classes of equivalency of their elements defined accordin... more Complex systems can be characterized by classes of equivalency of their elements defined according to system specific rules. We propose a generalized preferential attachment model to describe the class size distribution. The model postulates preferential growth of the existing classes and the steady influx of new classes. According to the model, the distribution changes from a pure exponential form for
We investigate the impact of borders on the topology of spatially embedded networks. Indeed terri... more We investigate the impact of borders on the topology of spatially embedded networks. Indeed territorial subdivisions and geographical borders significantly hamper the geographical span of networks thus playing a key role in the formation of network communities. This is especially important in scientific and technological policy making and highlights the interplay of the internationalization pressure toward a global innovation system against the administrative borders imposed by the national and continental institutions. In this study we introduce an outreach index to quantify the impact of borders on the community structure and apply it to the case of the European and US patent co-inventors networks. We find that (a) the US connectivity decays as a power of distance, whereas we observe a faster exponential decay for Europe; (b) European network communities essentially correspond to nations and contiguous regions while US communities span multiple states across the whole country without any characteristic geographic scale. We confirm our findings by means of a set of simulations aimed at exploring the relationship between different patterns of crossborder community structures and the outreach index. Moreover, our approach represents a new type of comparative analytical framework for spatially embedded networks.
The research effort undertaken by firms is driven b y a multiple set of factors and incentives. T... more The research effort undertaken by firms is driven b y a multiple set of factors and incentives. The debate in the theoretical literature has focused th e attention on "technology push" versus "demand pull" theories, the former considering the exogenou s effect of science on technological change, while the latter regarding market growth and size a s unique determinants of the decision to invest in R&D. Both theories tell only part of the story. The decision to invest in R&D, and therefore the rate and direction of technological progress, is the res ult of the interplay between the advances spanning from basic science 2, institutional variables, and economic factors, na mely market growth and size (Dosi, 1982, 1988). Despite the theoretical attention and importance at tached to this issue, little empirical evidence is provided on the role of demand and science in affec ting the rate of technological progress. In this paper we investigate the pharmaceutical ind ustr...
We study the betweenness centrality of fractal and non-fractal scale-free network models as well ... more We study the betweenness centrality of fractal and non-fractal scale-free network models as well as real networks. We show that the correlation between degree and betweenness centrality C of nodes is much weaker in fractal network models compared to non-fractal models. We also show that nodes of both fractal and non-fractal scale-free networks have power law betweenness centrality distribution P(C)
This paper analyses the propensity to withdraw European patent applications within a regional sam... more This paper analyses the propensity to withdraw European patent applications within a regional sample of Italian applicants. The procedure for obtaining a granted patent from the EPO is composed of a series of sequential and selective steps imposing additional costs to the applicants. Accordingly, we argue that early withdrawals - i.e. those occurring before the proper examination process begins - should be treated separately from late withdrawals. Our findings show the probability of an early withdrawal is higher for applicants with lower resources and competencies and rises with the number of backward citations added by EPO examiners to the original application. Late withdrawals, instead, are negatively affected by one factor only: the size of patent family, which approximates the sunk costs born by applicants in order to extend the geographical scope of patent protection. Such a limited explanation suggests that the interventions of EPO examiners are likely to play a significant r...
R&D, Innovation and Competitiveness in the European Chemical Industry, 2004
Chapter 7 THE NATURE AND THE EXTENT OF THE MARKET FOR TECHNOLOGYIN BIOPHARMACEUTICALS Ashish Aror... more Chapter 7 THE NATURE AND THE EXTENT OF THE MARKET FOR TECHNOLOGYIN BIOPHARMACEUTICALS Ashish Arora, Alfonso Gambardella, Fabio Pammolli and Massimo Riccaboni Carnegie Mellon University, St. Anna School of Advanced Studies, University of Florence-CERMand ...
In this paper, we investigate how underlying relevant technological conditions induce distinguish... more In this paper, we investigate how underlying relevant technological conditions induce distinguishable patterns of change in industry structure and evolution. A mapping is detected between the specific nature of problem decompositions and research techniques at the micro level of knowledge bases, and patterns of structural evolution at the macro level of the industry network. The graph-theoretic techniques we introduce map major technological discontinuities on changes observed at the level of dominant organization forms. They might have applications in other domains, whenever the identification of structural breaks and homological relationships between technological and industrial spaces are important issues. q F. Pammolli . 0048-7333r01r$ -see front matter q 2001 Elsevier Science B.V. All rights reserved.
The report examines the competitive position of the European pharmaceutical companies and industr... more The report examines the competitive position of the European pharmaceutical companies and industries, and compares them with the pharmaceutical companies and industries in other parts of the world, particularly the US. Over the last two decades, the industry has experienced some important structural changes, mainly driven by technological and institutional shocks that have affected all the stages of its value
An explosion of knowledge and a growing array of tools and technologies have transformed modern d... more An explosion of knowledge and a growing array of tools and technologies have transformed modern drug R&D, while its cost has risen by a sizable amount. At the same time, the unchecked increase in health care and prescription drug spending has spawned cost containment policies that are restricting the demand for drugs in all major markets. This Perspective explores the interplay between technological advances and regulatory policies and their likely impact on the dynamics of the pharmaceutical industry.
We test recent theory on the benefits of auctions and bargaining as alternative procurement mecha... more We test recent theory on the benefits of auctions and bargaining as alternative procurement mechanisms using data on the procurement of medical devices by Italian hospitals. Theory suggests that auctions perform well when cost control is the key concern, but are less effective at producing the optimal mix of quality and price for complex products where quality is difficult to
We refer to the framework developed by and to the notion of independent submarkets (Sutton 1998) ... more We refer to the framework developed by and to the notion of independent submarkets (Sutton 1998) to provide a simple candidate explanation for the shape of the firm growth distribution based on a model of proportional growth at the level of both the introduction of new products by firms and their size dynamics. We exploit the features of a unique longitudinal data set which covers the entire distribution of products and firms in the worldwide pharmaceutical industry to test the model at different levels of aggregation as well as at different time lags. Econometric investigations show that the model's predictions are in good agreement with empirical evidence. (JEL: L11, L65) (EPRIS Program) is gratefully acknowledged for financial support.
Complex systems can be characterized by classes of equivalency of their elements defined accordin... more Complex systems can be characterized by classes of equivalency of their elements defined according to system specific rules. We propose a generalized preferential attachment model to describe the class size distribution. The model postulates preferential growth of the existing classes and the steady influx of new classes. According to the model, the distribution changes from a pure exponential form for
We investigate the impact of borders on the topology of spatially embedded networks. Indeed terri... more We investigate the impact of borders on the topology of spatially embedded networks. Indeed territorial subdivisions and geographical borders significantly hamper the geographical span of networks thus playing a key role in the formation of network communities. This is especially important in scientific and technological policy making and highlights the interplay of the internationalization pressure toward a global innovation system against the administrative borders imposed by the national and continental institutions. In this study we introduce an outreach index to quantify the impact of borders on the community structure and apply it to the case of the European and US patent co-inventors networks. We find that (a) the US connectivity decays as a power of distance, whereas we observe a faster exponential decay for Europe; (b) European network communities essentially correspond to nations and contiguous regions while US communities span multiple states across the whole country without any characteristic geographic scale. We confirm our findings by means of a set of simulations aimed at exploring the relationship between different patterns of crossborder community structures and the outreach index. Moreover, our approach represents a new type of comparative analytical framework for spatially embedded networks.
The research effort undertaken by firms is driven b y a multiple set of factors and incentives. T... more The research effort undertaken by firms is driven b y a multiple set of factors and incentives. The debate in the theoretical literature has focused th e attention on "technology push" versus "demand pull" theories, the former considering the exogenou s effect of science on technological change, while the latter regarding market growth and size a s unique determinants of the decision to invest in R&D. Both theories tell only part of the story. The decision to invest in R&D, and therefore the rate and direction of technological progress, is the res ult of the interplay between the advances spanning from basic science 2, institutional variables, and economic factors, na mely market growth and size (Dosi, 1982, 1988). Despite the theoretical attention and importance at tached to this issue, little empirical evidence is provided on the role of demand and science in affec ting the rate of technological progress. In this paper we investigate the pharmaceutical ind ustr...
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