* * Preprint Version * *

      January 2003

(full text)



Mapping Global Science Using International Co-authorships:

A Comparison of 1990 and 2000


Caroline S. Wagner and Loet Leydesdorff

Science & Technology Dynamics, University of Amsterdam

Amsterdam School of Communications Research (ASCoR),

Kloveniersburgwal 48, 1012 CX  Amsterdam, The Netherlands.


Using the Science Citation Index (CD-Rom version) for 1990 and 2000, this paper analyses international co-authorships. The paper presents the methodology for identifying these co-authorships.  Analysis is presented on observed linkages at the global level and on regional bases.  The architecture of the network is further explored using statistical methods and factor analysis to reveal intense relationships as well as the core members of a global network.  Findings show that, in the 10 years between 1990 and 2000, the global network has expanded to include more nations and it has become more interconnected.  Regional networks show emerging hubs.  Within the global network, a core set of countries has expanded from six in 1990 to eight in 2000.  Factor analysis suggests that large countries compete with each other for partners in the global network.  We discuss implications for public policy of the rise of a global network of scientists operating somewhat independently of national interests