- Technological change, Inventions, Green Technology, Innovation, Patents, R&D, Climate Change Adaption and Mitigation Strategies, Urban Studies, and 7 moreMetropolitan Scale, Urban Economics, Social Network Inventor, Inventor Networks, Renewable Energy Systems, Complex Systems, and Complex Systems Scienceedit
- I have a longstanding interest in the study of technological change, invention and innovation, particularly in how th... moreI have a longstanding interest in the study of technological change, invention and innovation, particularly in how they relate to sustained economic growth in cities. Recently, I have focused more on technological change in renewable energy systems and what role technological change and innovation can play in climate adaptation and mitigation strategies. My current work examines the ability of AI to augment inventor's capabilities, and the potential for AI system to create novel invention independently. I greatly enjoy teaching quantitative methods and incorporating techniques from complex adaptive systems in my work (such as social network analysis, allometric scaling, agent based models, big data analysis, GIS & spatial statistics).edit
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ABSTRACTOn the premise that knowledge creation defines contemporary metropolitan regions, we profile them by their inventive networks, as measured by a variety of complementary social network, technology, and patenting metrics that... more
ABSTRACTOn the premise that knowledge creation defines contemporary metropolitan regions, we profile them by their inventive networks, as measured by a variety of complementary social network, technology, and patenting metrics that distinguish scalar and structural aspects. Using a comprehensive, multiyear database of patent applications, we investigate whether the knowledge creation network profiles are discriminating characteristics of metropolitan regions by establishing a new urban taxonomy for metropolitan areas in the United States. The four‐class taxonomy is not only statistically significant, but it is also economically meaningful in terms of economic performance of metropolitan areas. We find that metropolitan areas benefit from a higher density of inventors in the population, and that there is a positive correlation between economic performance and metropolitan areas with inventor teams working in similar or complementary areas of technology. In fact, the structure of knowledge creation networks are fundamental to economic performance and extends to metropolitan growth rates in jobs and income.
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An essential feature of a modern patenting system is a classification schema for organizing, indexing and coding the technical information contained in a patent. Patent classification systems make it possible for patent examiners and... more
An essential feature of a modern patenting system is a classification schema for organizing, indexing and coding the technical information contained in a patent. Patent classification systems make it possible for patent examiners and prospective inventors to search through existing patents in order to find information pertinent to evaluating a patent application’s purported novelty. Patent classification systems also support the construction of a taxonomy for the various sources of inventive novelty embodied in patented inventions. Until 2013 the U.S. Patent Office utilized the United States Patent Classification system and since then it has used the Cooperative Patent Classification (CPC) system; these two systems implement very different classification logics with the CPC aiming at greater granularity. Here we examine the extent to which the two patent classification systems generate similar historical narratives as to the sources of inventive novelty. Despite the differences in classification principles, common patterns are revealed regardless of which classification system is used to identify technologies. Invention is primarily a cumulative process where new inventions are developed from combining existing technologies. Refinements (the re-use of existing technologies) and combinations of previously existing technological functionalities predominate in the patent record, while inventions embodying previously unseen technologies are very rare. The rate at which inventions representing non-refinements have been introduced into the stock of inventions has kept pace with the generation of inventions representing refinements, thereby feeding the combinatorial process.
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Sustainable urban systems (SUS) science is a new science integrating work across established and emerging disciplines, using diverse methods, and addressing issues at local, regional, national, and global scales. Advancing SUS requires... more
Sustainable urban systems (SUS) science is a new science integrating work across established and emerging disciplines, using diverse methods, and addressing issues at local, regional, national, and global scales. Advancing SUS requires the next generation of scholars and practitioners to excel at synthesis across disciplines and possess the skills to innovate in the realms of research, policy, and stakeholder engagement. We outline key tenets of graduate education in SUS, informed by historical and global perspectives. The sketch is an invitation to discuss how graduates in SUS should be trained to engage with the challenges and opportunities presented by continuing urbanization.
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Agglomeration is the tell-tale sign of cities and urbanization. Identifying and measuring agglomeration economies has been achieved by a variety of means and by various disciplines, including urban economics, quantitative geography, and... more
Agglomeration is the tell-tale sign of cities and urbanization. Identifying and measuring agglomeration economies has been achieved by a variety of means and by various disciplines, including urban economics, quantitative geography, and regional science. Agglomeration is typically expressed as the non-linear dependence of many different urban quantities on city size, proxied by population. The identification and measurement of agglomeration effects is of course dependent on the choice of spatial units. Metropolitan areas (or their equivalent) have been the preferred spatial units for urban scaling modeling. The many issues surrounding the delineation of metropolitan areas have tended to obscure that urban scaling is principally about the measurable consequences of social and economic interactions embedded in physical space and facilitated by physical proximity and infrastructure. These generative processes obviously must exist in the spatial subcomponents of metropolitan areas. Using data for counties and urbanized areas in the United States, we show that the generative processes that give rise to scaling effects are not an artifact of metropolitan definitions and exist at smaller spatial scales.
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This is a report on the discussions held during an NSF SUS conference “Graduate Education for a New Sustainable Urban Systems Science: Designing a New PhD Curriculum Integrating Sustainability Science and Urban Science”. The conference... more
This is a report on the discussions held during an NSF SUS conference “Graduate Education for a New Sustainable Urban Systems Science: Designing a New PhD Curriculum Integrating Sustainability Science and Urban Science”. The conference was motivated by the call made by the NSF for “…developing the next generation of sustainable urban systems science.” (NSF 2018) The conference was premised on the assumption that such continued development will require the training of new generations of urban sustainability scientists, and that both the content and manner of training will be different from established degree programs.
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Urban economies are composed of diverse activities, embodied in labor occupations, which depend on one another to produce goods and services. Yet little is known about how the nature and intensity of these interdependences change as... more
Urban economies are composed of diverse activities, embodied in labor occupations, which depend on one another to produce goods and services. Yet little is known about how the nature and intensity of these interdependences change as cities increase in population size and economic complexity. Understanding the relationship between occupational interdependencies and the number of occupations defining an urban economy is relevant because interdependence within a networked system has implications for system resilience and for how easily can the structure of the network be modified. Here, we represent the interdependencies among occupations in a city as a non-spatial information network, where the strengths of interdependence between pairs of occupations determine the strengths of the links in the network. Using those quantified link strengths we calculate a single metric of interdependence-or connectedness-which is equivalent to the density of a city's weighted occupational network....
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Understanding cities is central to addressing major global challenges from climate change to economic resilience. Although increasingly perceived as fundamental socio-economic units, the detailed fabric of urban economic activities is... more
Understanding cities is central to addressing major global challenges from climate change to economic resilience. Although increasingly perceived as fundamental socio-economic units, the detailed fabric of urban economic activities is only recently accessible to comprehensive analyses with the availability of large datasets. Here, we study abundances of business categories across US metropolitan statistical areas, and provide a framework for measuring the intrinsic diversity of economic activities that transcends scales of the classification scheme. A universal structure common to all cities is revealed, manifesting self-similarity in internal economic structure as well as aggregated metrics (GDP, patents, crime). We present a simple mathematical derivation of the universality, and provide a model, together with its economic implications of open-ended diversity created by urbanization, for understanding the observed empirical distribution. Given the universal distribution, scaling a...
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An analysis of national and metropolitan area invention from 1980 to 2012, using a new comprehensive database of patents, reveals: n The rate of patenting in the United States has been increasing in recent decades and stands at... more
An analysis of national and metropolitan area invention from 1980 to 2012, using a new comprehensive database of patents, reveals: n The rate of patenting in the United States has been increasing in recent decades and stands at historically high levels. Growth in patent applications slowed after the IT bubble and the Great Recession, but the rate of patenting by U.S. inventors is at its highest point since the Industrial Revolution. Moreover, patents are of objectively higher value now than in the recent past and more evenly dispersed among owners than in previous decades. Still, the United States ranks just ninth in patents per capita using appropriate international metrics, as global competition has increased. n Most U.S. patents—63 percent—are developed by people living in just 20 metro areas, which are home to 34 percent of the U.S. population. Reflecting the advantages of large metropolitan economies, 92 percent of U.S. patents are concentrated in just 100 metro areas, with 59 ...
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Invention has been commonly conceptualized as a search over a space of combinatorial possibilities. Despite the existence of a rich literature, spanning a variety of disciplines, elaborating on the recombinant nature of invention, we lack... more
Invention has been commonly conceptualized as a search over a space of combinatorial possibilities. Despite the existence of a rich literature, spanning a variety of disciplines, elaborating on the recombinant nature of invention, we lack a formal and quantitative characterization of the combinatorial process underpinning inventive activity. Here we utilize U.S. patent records dating from 1790 to 2010 to formally characterize the invention as a combinatorial process. To do this we treat patented inventions as carriers of technologies and avail ourselves of the elaborate system of technology codes used by the U.S. Patent Office to classify the technologies responsible for an invention's novelty. We find that the combinatorial inventive process exhibits an invariant rate of "exploitation" (refinements of existing combinations of technologies) and "exploration" (the development of new technological combinations). This combinatorial dynamic contrasts sharply with the creation of new technological capabilities -- the building blocks to be combined -- which has significantly slowed down. We also find that notwithstanding the very reduced rate at which new technologies are introduced, the generation of novel technological combinations engenders a practically infinite space of technological configurations.
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Understanding cities is central to addressing major global challenges from climate change to economic resilience. Although increasingly perceived as fundamental socioeconomic units, the detailed fabric of urban economic activities is only... more
Understanding cities is central to addressing major global challenges from climate change to economic resilience. Although increasingly perceived as fundamental socioeconomic units, the detailed fabric of urban economic activities is only recently accessible to comprehensive analyses with the availability of large datasets. Here, we study abundances of business categories across US metropolitan statistical areas, and provide a framework for measuring the intrinsic diversity of economic activities that transcends scales of the classification scheme. A universal structure common to all cities is revealed, manifesting self-similarity in internal economic structure as well as aggregated metrics (GDP, patents, crime). We present a simple mathematical derivation of the universality, and provide a model, together with its economic implications of open-ended diversity created by urbanization, for understanding the observed empirical distribution. Given the universal distribution, scaling analyses for individual business categories enable us to determine their relative abundances as a function of city size. These results shed light on the processes of economic differentiation with scale, suggesting a general structure for the growth of national economies as integrated urban systems.
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ABSTRACT
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Invention has been commonly conceptualized as a search over a space of combinatorial possibilities. Despite the existence of a rich literature, spanning a variety of disciplines, elaborating on the recombinant nature of invention, we lack... more
Invention has been commonly conceptualized as a search over a space of combinatorial possibilities. Despite the existence of a rich literature, spanning a variety of disciplines, elaborating on the recombinant nature of invention, we lack a formal and quantitative characterization of the combinatorial process underpinning inventive activity. Here, we use US patent records dating from 1790 to 2010 to formally characterize invention as a combinatorial process. To do this, we treat patented inventions as carriers of technologies and avail ourselves of the elaborate system of technology codes used by the United States Patent and Trademark Office to classify the technologies responsible for an invention's novelty. We find that the combinatorial inventive process exhibits an invariant rate of 'exploitation' (refinements of existing combinations of technologies) and 'exploration' (the development of new technological combinations). This combinatorial dynamic contrasts s...
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ABSTRACT This paper discusses the history of innovation as it is revealed through an analysis of the US patent database. I highlights different types of technological innovation and analyzes what role specific metropolitan... more
ABSTRACT This paper discusses the history of innovation as it is revealed through an analysis of the US patent database. I highlights different types of technological innovation and analyzes what role specific metropolitan regionsinnovation hubshave played in the long-term patterns of technological, scientific and social change.
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ABSTRACT Creative and inventive individuals are the principal inputs for the generation of ideas which ought to imply the presence of a strong “scale effects” in the production of new ideas. Identifying the relationship between population... more
ABSTRACT Creative and inventive individuals are the principal inputs for the generation of ideas which ought to imply the presence of a strong “scale effects” in the production of new ideas. Identifying the relationship between population size and idea generation is difficult at the level of national economies due to the many confounding factors. This paper is motivated by the question of whether there are scale effects in the production of new ideas in urban economies. Patenting activity is a privileged data source as both the production of ideas and who the producers are can be tracked with very high precision. The very high levels of economic, social, institutional, political and cultural integration among the urban areas of the United States provide the conditions to investigate whether there is positive a feedback loop between population and ideas. The evidence presented indicates that both the level and growth rate of urban patents are positively affected by the size of the inventive labor force but the effect is less than proportional (in the case of initial number of inventors) or proportional (when measuring the effect of growth of inventors). The story of urban patenting one of scale effects but without increasing returns. What we know about how patenting gets done, and who does it, provide the micro foundations for the results presented here.
DOI: 10.1080/00420980220135527 2002 39: 1129 Urban Stud Matthew Drennan, Shannon Larsen, Jose Lobo, Deborah Strumsky and Wahyu Utomo 1969-96 Sectoral Shares, Specialisation and Metropolitan Wages in the United States, ... On behalf of:... more
DOI: 10.1080/00420980220135527 2002 39: 1129 Urban Stud Matthew Drennan, Shannon Larsen, Jose Lobo, Deborah Strumsky and Wahyu Utomo 1969-96 Sectoral Shares, Specialisation and Metropolitan Wages in the United States, ... On behalf of: Urban Studies Journal ...