International Knowledge Flows and the Role of Proximity

International knowledge flows have become increasingly common and more frequent and are a key driving force promoting the development of global science. However, little attention has been paid to the determinants of international scientific collaboration. Using co-publication data from the Web of Science database in the period 2000-2014, this paper illustrates spatial patterns of international knowledge flows and estimates the impact of geographical, technological, social, and cultural proximity on the variation of inter-country collaboration in science. Our findings demonstrate that the coefficients of the four dimensions of proximity are positive and significant in panel estimates and cross-section estimatesinternational knowledge flows are facilitated by geographical, technological, social, and cultural proximity. We also find that the effect of geographical and cultural proximity have waned over time, while the impact of social and technological proximity have strengthened.