The Generalizability of IR Experiments Beyond the U.S.

Theories of international relations (IR) typically make predictions intended to hold across many countries. Nonetheless, existing experimental evidence testing the micro-foundations of IR theories relies overwhelmingly on studies fielded in the U.S. We argue that the nature of what constitutes a theory of IR makes it particularly important to know whether theories hold across countries. To examine the generalizability of IR experimental findings beyond the U.S., we implemented a pre-registered and harmonized multi-site replication study, fielding four prominent IR experiments in seven countries: Brazil, Germany, India, Israel, Japan, Nigeria, and the U.S. We find that all four experiments replicate in nearly all of the countries, a pattern likely due to treatment effect homogeneity. Our study not only reveals that findings from the U.S. are similar to findings from a wide range of countries, but offers important implications for the design and interpretation of future experimental research in IR.