The role of local colleagues in establishing international scientific collaboration: Social capital in emerging science systems

International collaborations are important for developing science systems. Using a dataset of South African university scientists, we ask whether social capital relevant to international collaboration held by one scientist spills over to local colleagues. Distinguishing between different ways of acquiring foreign ties, we find that 20% of our cases resemble the most-studied form of international collaborations, via the unique ties of an individual with specific characteristics, e.g., foreign research training. In all other cases, both personal and local peers' international social capital is relevant for foreign tie formation. Underlining the systemic functioning of science, international social capital is activated through scientific collaboration among local scientists. The mediating effect of local scientific collaboration is present across all scientific fields and holds for scientists trained locally or abroad. Our findings thus imply that local collaboration is a relevant mechanism to strengthen international collaboration and the formation of international social capital.