Long-run dynamics of the U.S. patent classification system

Almost by definition, radical innovations create a need to revise existing classification systems. In this paper, we argue that classification system changes and patent reclassification are common and reveal interesting information about technological evolution. To support our argument, we present three sets of findings regarding classification volatility in the U.S. patent classification system. First, we study the evolution of the number of distinct classes. Reconstructed time series based on the current classification scheme are very different from historical data. This suggests that using the current classification to analyze the past produces a distorted view of the evolution of the system. Second, we study the relative sizes of classes. The size distribution is exponential so classes are of quite different sizes, but the largest classes are not necessarily the oldest. To explain this pattern with a simple stochastic growth model, we introduce the assumption that classes have a regular chance to be split. Third, we study reclassification. The share of patents that are in a different class now than they were at birth can be quite high. Reclassification mostly occurs across classes belonging to the same 1-digit NBER category, but not always. We also document that reclassified patents tend to be more cited than non-reclassified ones, even after controlling for grant year and class of origin

Returns to Inventors

A key input to inventive activity is human capital. Hence it is important to understand the monetary incentives of inventors. We estimate the effect of patented inventions on individual earnings by linking data on U.S. patents and their inventors to Finnish employer-employee data. Returns are heterogeneous: Inventors get a temporary reward of 3% of annual earnings for a patent grant and for highly-cited patents a longer-lasting premium of 30% in earnings three years later. Similar medium-term premia accrue to inventors who initially hold the patent rights, although they forego earnings at the time of the grant

Knowledge Flows and Productivity

National and international flows of knowledge are fundamental determinants of technological progress. In this article we review the existing literature on knowledge flows and we propose a method for estimating them, based on patent citations. Citations are links between inventions that reveal a learning process at the technological frontier. We use data for the period 1975-1996 for 147 subnational regions in Europe and North America. We find that geographical distance and technological differences constitute major barriers to knowledge flows. We also show that these flows may have positive, but small, effect on total factor productivity.

Technology Mobility and Job Mobility A comparative analysis between patent and survey data

In recent years, increasing attention and resources have been devoted to the analysis of workers’ mobility and the collection of new and extensive datasets in order to monitor and appraise this phenomenon. Most of the studies make use of information about inventors extracted from patent data. In fact, patent data collects detailed information on inventors, their geographical location and the applicants of their patents. This paper instead makes use of unique data on inventors’ curriculum vitae collected through a survey addressed to a group of Italian inventors in the pharmaceutical field and compares this information to those extracted from patent data. Results seem to challenge the traditional interpretation of mobility phenomena based on patent data and suggest that patent and survey data might capture different aspects of inventors’ career path. In particular, results indicate that survey data describes the whole set of inventors’ employers and the knowledge flows across them. Conversely, patent data portrays a different set that is the one composed of those actors directly involved in inventive processes and participating to the production of patented knowledge. More interestingly, they overlap only partially and do not necessarily coincide.Patent; Mobility; Inventor

Research Scientist Productivity and Firm Size: Evidence from Panel Data on Investors

It has long been recognized that worker wages and possibly productivity are higher in large firms. Moreover, at least since Schumpeter (1942) economists have been interested in the relative efficiency of large firms in the research and development enterprise. This paper uses longitudinal worker-firm-matched data to examine the relationship between the productivity of workers specifically engaged in innovation and firm size in the pharmaceutical and semiconductor industries. In both industries, we find that inventors' productivity increases with firm size. This result holds across different specifications and even after controlling for inventors' experience, education, the quality of other inventors in the firm, and other firm characteristics. We find evidence in the pharmaceutical industry that this is partly accounted for by differences between how large and small firms organize R&D activities.Patents; Innovation; Labor productivity; Research; Firm size

The Patterns of Inter-firm and Inter-industry Knowledge Flows in the Netherlands

This paper presents a study of backward and forward patent citations in patents granted to firms and institutions in the Netherlands by the United States Patent and Trademark Office (USPTO). The study establishes different patterns of patent citation in recent Dutch patents belonging to different industrial classes. We run our model in the set of backward citations made in Dutch applicants’ patents during 1996-2006 and in the set of forward citations to patents issued to firms and organizations in the Netherlands during 1993-2006. We compare the patterns of knowledge utilization (represented by backward patent citations) and knowledge dissemination (represented by forward patent citations) and obtain evidence of inter- or intra-firm and inter- or intra-industry knowledge spillovers. In the context of effective competition and innovation policies we advocate for paying special attention to industry specifics when designing policy programs and measures directed at stimulating R&D cooperation and knowledge spillovers. We present evidence that policies for promoting better knowledge exchange among firms should also distinguish between the measures for promoting the inward and the outward knowledge flows for companies in the Netherlands.knowledge flows, R&D spillovers, backward and forward patent citations

Does it matter where patent citations come from? Inventor versus examiner citations in European patents

This paper investigates whether the distinction between patent citations added by the inventor or the examiner is relevant for the issue of geographical concentration of knowledge flows (as embodied in citations). The distinction between inventor and examiner citations enables us to work with a more refined citation indicator of knowledge flows. We use information in the search reports of patent examiners at the European Patent Office to construct our dataset of regional patenting in Europe, and apply various econometric models to investigate our research question. The findings point to a significant localization effect of inventor citations, after controlling for various other factors, and hence suggest that knowledge flows are indeed geographically concentrated. This holds true also for a sub-sample of patents owned by 169 large multinational enterprises (MNEs). The results for the sample of MNEs suggest that multinational firms seek out specific regional knowledge specializations (and hence at least partly reinforce geographical concentration), but are also able to transfer knowledge "easier" over larger distances.research and development ;

The International Dynamics of R&D and Innovationin the Short Run and in the Long Run

In this paper we estimate the dynamic relationship between employment in R&D and generation of knowledge as measured by patent applications across OECD countries. In several recently developed models, known as ‘idea-based’ models of growth, the afore mentioned ""ideagenerating"" process is the engine of productivity growth. Moreover, in real business cycle models technological shocks are an important source of fluctuations. Our empirical strategy is able to test whether knowledge spillovers are strong enough to generate sustained endogenous growth and to estimate the quantitative impact of international knowledge on technological innovation of a country in the short and in the long run. We find that a country’s stock of knowledge, its R&D resources and the stock of international knowledge move together in the long run. International knowledge has a very significant impact on innovation. As a consequence, a positive shock to R&D in the US (the largest world innovator) has a significant positive effect on the innovation of all other countries. Such a shock produces its largest effect on domestic and international innovation after five to ten years from its occurrence.Innovation, Weak Scale Effects, Panel Cointegration, Error Correction Mechanism,International Knowledge Spillovers

Returns to Inventors

A key input to inventive activity is human capital. Hence it is important to understand the monetary incentives of inventors. We estimate the effect of patented inventions on individual earnings by linking data on U.S. patents and their inventors to Finnish employer-employee data. Returns are heterogeneous: Inventors get a temporary reward of 3% of annual earnings for a patent grant and for highly-cited patents a longer-lasting premium of 30% in earnings three years later. Similar medium-term premia accrue to inventors who initially hold the patent rights, although they forego earnings at the time of the grant.citations; effort; incentives; inventors; intellectual property; patents; performance pay; return; wages

The International Dynamics of R&D and Innovation in the Short and in the Long Run

In this paper we estimate the dynamic relationship between employment in R&D and generation of knowledge as measured by patent applications across OECD countries. In several recently developed models, known as `idea-based' models of growth, the afore mentioned "idea-generating" process is the engine of productivity growth. Moreover, in real business cycle models technological shocks are an important source of fluctuations. Our empirical strategy is able to test whether knowledge spillovers are strong enough to generate sustained endogenous growth and to estimate the quantitative impact of international knowledge on technological innovation of a country in the short and in the long run. We find that a country's stock of knowledge, its R&D resources and the stock of international knowledge move together in the long run. International knowledge has a very significant impact on innovation. As a consequence, a positive shock to R&D in the US (the largest world innovator) has a significant positive effect on the innovation of all other countries. Such a shock produces its largest effect on domestic and international innovation after five to ten years from its occurrence.