networks (Shin and Park 2007 ; Wartburg et al. 2005 ; Yoon and Park 2004 ). A patentcitation network consists of groups of related patents in which the largest groups are defined by patent technology categories. The exchange of citations between these
Authors:Show-Ling Jang, Yun-Chen Yu and Tzu-Ya Wang
, technology diffusers. We find that activeness in learning has a significantly positive impact on the relative importance of e-paper display technology within the knowledge network. Firms engaging in intensive patentcitation activities with the aim of
Despite strategic research has been done in recent years to study how network topology shapes the evolution of competition
in various industries, previous researches do not investigate the importance of high betweenness point on the connectivity
of patent citation networks. The goal of this report is to examine and characterize the small world phenomenon in the patent
citations network by analyzing the data of RFID patents. The results suggest that the patent citation network can indeed be
characterized as “small world”. Additionally, the patent citation network resembles the power-law connectivity distribution
and exhibits preferential connectivity behavior. In other words, a few key patents have a great many more connections than
the majority of patents with few connections. Furthermore, the patents of high betweenness centrality were identified. It
is found that 81% of the patent citation activities have relations with the patents of high betweenness centrality. The result
of this analysis will provide a specific way for managers to identify key patents, to map their own patent deployment and
to derive insight into the best ways to navigate within such networks.
citations are extensively used as a measure of patent quality. However,
counting citations does not account for the fact that citations come from
patents of different qualities, and that citations are of variable qualities.
We develop a citation index which takes into account the cumulative quality of
the citing patents. We apply this index to the 2,139,314 utility patents
granted in the U.S. between 1975 and 1999. We study the properties of this
index by year and by technological category, and analyse the links between
The emergence of pattent bibliometrics as a new branch of scientometrics necessitates a deeper understanding of the relationship between patents and papers. As this connection is established through the linkage between patents and research papers, one must have a clear idea of similarities and differences between patent and paper citations. This paper will investigate to what extent one can not only apply bibliometric methods to patents but also extend the existing interpretative framework for citations in research papers to the field of patent citations. After pointing out some parallels in the debates about the nature of citations in patents and scientific articles, the paper outlines those parts of bibliometric theory covering scientific citations that could be relevant to patent citations too. Then it highlights the specialties and peculiarities of patent citations. One major conclusion is that the general nature of a common framework for both scientific and patent citations would severely limit its usefulness, but research on academic citations might still be a great source of inspiration to the study of patent citations.
citations to measure patent quality (Trajtenberg 1990 ; Hagedoorn and Cloodt 2003 ; Lanjouw and Schankerman 2004 ; Hall et al. 2005 ). This study argues that there is a threshold effect of patentcitations/sales on the relationship between patent counts
Authors:Yong-Gil Lee, Jeong-Dong Lee, Yong-Il Song and Se-Jun Lee
Patent citation counts represent an aspect of patent quality and knowledge flow. Especially, citation data of US patents contain
most valuable pieces of the information among other patents. This paper identifies the factors affecting patent citation counts
using US patents belonging to Korea Institute of Science and Technology (KIST). For patent citation count model, zero-inflated
models are announced to handle the excess zero data. For explanatory factors, research team characteristics, invention-specific
characteristics, and geographical domain related characteristics are suggested. As results, the size of invention and the
degree of dependence upon Japanese technological domain significantly affect patent citation counts of KIST.
Authors:Manuel Acosta, Daniel Coronado and Ana Fernández
In this paper we carry out an empirical analysis to address some questions concerning the production and quality of technology
in environmental sectors. The methodology involves patents as a measure of the generation of new knowledge, and patent citations
as a proxy for the quality of a technological invention. The sample contains more than 12,000 environmental European patents
from firms and government institutions from 1998 to 2004. From our econometric analysis, we found that environmental patents
applied by individual inventors present on average less quality that those applied by institutional inventors. The size of
family patent is relevant to explain forward patent citation. Furthermore, patents coming from abroad (out of Europe), in
particular with US and Japan priority, are more cited on average than local patents (with European priority). Lastly, the
specialization in environmental fields of a patent plays a negative role in determining the frequency of forward citation.
Authors:Mu-Hsuan Huang, Li-Yun Chiang and Dar-Zen Chen
This paper uses bibliographic coupling analysis to plot out a patent citation map. It explores the current research and development
in the high-tech electronic companies in Taiwan, and the relationship between companies and industries. Fifty-eight high-tech
electronic companies under this study, between 1998 and 2000, obtained 4162 patents from U.S., and cited 24,852 patents during
these years. Through the data from bibliographic coupling analysis, the paper categorizes these companies into 6 major groups:
semiconductor, peripheral, scanners, notebook / monitor, system, IC design / packaging. This research also uses multidimensional
scaling to plot out a patent citation map, graphically displaying the association among the groups. The result shows a higher
similarity among companies in semiconductor sector, whereas the distinction between industries grows more and more ambivalent,
even overlapping in some cases.
This paper investigates the impact of large multinational firms on the Dutch technology infrastructure. More specifically, it asks how the structure of the knowledge flows network matters for diffusion of technological knowledge in the Dutch economy. Patent citation analysis based on European Patent applications is used to quantify this network. The paper finds that there are large differences between firms in terms of the density of their 'ego-network', and the amount of knowledge spillovers to the Dutch economy that they generate.