In this paper we exploit new data on US inventors in Organic Chemistry, Pharmaceuticals, and Biotechnology to revisit the JTH test of the localization of knowledge spillovers (Jaffe, Trajtenberg, and Henderson; 1993). We find that inventors who patent across different companies contribute extensively to the observed citation patterns, both directly (through personal self-citations) and indirectly, by linking the various companies via a social network conducive to more citations. To the extent that the geographical mobility of these “cross-firm” inventors is quite limited, the resulting social networks and citations patterns are found to be bounded in space. We conclude that spatial distance, as measured in the JTH experiment, is just a proxy for a much more important variable, such as social distance between inventors. In a similar vein, we show that technological distance, introduced by Thompson and Fox-Kean (2005) to question the soundness of the JTH experiment, is also a proxy of social distance.
Download Info
To download:
If you experience problems downloading a file, check if you have the
proper application to
view it first. Information about this may be contained
in the File-Format links below. In case of further problems read
the IDEAS help
page. Note that these files are not on the IDEAS
site. Please be patient as the files may be large.
Publisher Info
Paper provided by CESPRI, Centre for Research on Innovation and Internationalisation, Universita' Bocconi, Milano, Italy in its series CESPRI Working Papers with number
184.
Length: 32 pages Date of creation: Oct 2006 Date of revision:
Oct 2006 Handle: RePEc:cri:cespri:wp184
Contact details of provider: Postal: via Sarfatti, 25 - 20136 Milano - Italy Phone: +39.025836.3397 Fax: +39.025836.3399 Web page: http://www.cespri.unibocconi.it/
Order Information: Postal: E G E A - via R. Sarfatti, 25 - 20136 Milano -Italy
For technical questions regarding this item, or to correct its listing, contact: (Roberta Ometti).
References listed on IDEAS Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
Cited by: (explanations, Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.)