Abstract
While the process of integration of national systems into supranational systems has been
widely discussed, comprehensive indicators of such processes are largely lacking. The author
proposes a new indicator of integration using the mutual information formula of frequency
matrices of country-country interactions. The indicator measures the degree in which the
observed frequency distribution of interactions differs from the distribution of random
interaction (perfect integration). The indicator proposed here takes into account both intra-
national and international interactions to control for country differences in probabilities of
intra-national and international collaboration: in larger countries interaction is expected to
take place relatively more often at the national level because there exist more opportunities to
interact at the national level. Controlling for countries’ size avoids the drawback of other
indicators that typically show excessively high integration values for smaller countries.
The integration indicator is applied to data from the Science Citation Index on inter-
institutional collaborations in scientific output of the fifteen EU countries to analyse the
integration process of European science during the period 1993-2000. Evidence is found that
the European science system has indeed become more integrated. Further analysis shows that
the higher level of integration has resulted exclusively from a more evenly distributed pattern
of European collaborations, while the strong bias towards intra-national collaborations
persisted. The results also show that larger countries are typically better integrated than
smaller countries, which suggests that larger countries benefit from network externalities that
trigger collaboration from smaller countries. The use of indicators of integration for both
future academic research and science policy is elaborated.
Key-words: globalisation, European integration, information theory, mutual information,
scientometrics, research collaboration, science policy, network externalities
JEL-code: O38, O52, R11, R12, R15