Science Without Borders? Waxing and Waning Integration in Global Scientific Research and Innovation

This chapter analyzes recent trends in the international integration and fragmentation of science. We document the rise of global mobility, cross-border fellowships, and increasingly team-based, and capital-intensive research, alongside countervailing forces such as national security restrictions, geopolitical conflict, and restrictive immigration policies. Scientific research generates global spillovers, yet the institutions that finance and govern research are mainly national, creating tradeoffs between international openness and strategic control. Drawing on historical episodes and recent empirical research, we show that migration and international collaboration remain central drivers of scientific productivity and knowledge diffusion, while disruptions can have substantial and lasting costs. We also emphasize an important measurement gap as economic and health returns to science are increasingly well studied, yet there is less evidence on the national security consequences of openness and restriction. The chapter concludes by outlining key open questions for research on how global science will evolve considering increased geopolitical tension.