Epo vs. USPTO Citation Lags

20 Pages Posted: 20 Dec 2004

See all articles by Emanuele Bacchiocchi

Emanuele Bacchiocchi

Università degli Studi di Milano

Fabio Montobbio

iCRIOS - Bocconi University; Catholic University of Milan - Department of Economic Policy

Date Written: September 2004


This paper estimates the diffusion and obsolescence of technological knowledge by technological field, country and type of institutions that generates it. We use two comparable samples of patents and patent citations from the NBER U.S. Patent Citations Dataset (based on patents from the US Patent Office) and from the EP Cespri Dataset (based on patents from the European Patent Office). Using a quasi-structural model, as proposed by Caballero and Jaffe (1993) and discussed in Hall et al. (2001), we test whether the observed processes of knowledge diffusion and obsolescence reflect the specific institutional mechanism generating them. Results show that at the USPTO there are more citations per patent due to the different rules governing citation practices and that their median lag is twice as large relatively to the citations at the EPO. We also find that the relative properties of the citation frequencies in different technological fields change according to the patent office considered.

Keywords: Patent citations, knowledge flows, spillovers, diffusion, patent

JEL Classification: O30, O33, O34

Suggested Citation

Bacchiocchi, Emanuele and Montobbio, Fabio and Montobbio, Fabio, Epo vs. USPTO Citation Lags (September 2004). Available at SSRN: https://ssrn.com/abstract=632324 or http://dx.doi.org/10.2139/ssrn.632324

Emanuele Bacchiocchi (Contact Author)

Università degli Studi di Milano ( email )

Milan, 20122

Fabio Montobbio

iCRIOS - Bocconi University ( email )

Via Roentgen 1
20136 Milan, MI 20136

HOME PAGE: http://https://sites.google.com/site/montobbiofabio/

Catholic University of Milan - Department of Economic Policy ( email )

Largo Gemelli 1
Milan, MI Milano 20123

HOME PAGE: http://https://sites.google.com/site/montobbiofabio/

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