Frontier Knowledge and the Creation of Ideas: Evidence from the Collapse of International Science in the Wake of World War I

We quantify how access to frontier knowledge a effects the creation of ideas. We show that citing frontier knowledge is correlated with producing high-quality papers. Because this correlation may be driven by unobserved factors, we identify the causal effect of frontier knowledge by analyzing a sudden collapse of international scientific cooperation. We show that World War I and the subsequent boycott against Central scientists severely reduced the dissemination of international knowledge, including knowledge at the scientific frontier. We then estimate how the reduction of international knowledge flows affected the productivity of scientists. Specifically, we compare productivity changes for scientists who relied on frontier knowledge from abroad, to changes for scientists who relied on frontier knowledge from home. After 1914, scientists who relied on frontier knowledge from abroad published fewer papers in top science journals and produced less Nobel Prize-nominated research. Our results indicate that access to the very best research, the top 1%, is essential for scientific progress.