Replication Data for: Learning to Predict Proliferation

How effective are states at assessing and predicting the nuclear intentions of foreign countries? Drawing on close to 200 U.S. assessments of foreign countries’ proliferation intentions between 1957 and 1966, this research note finds that close to 80% of testable U.S. assessments were correct and that U.S. assessments shifted from highly inaccurate in the late 1950s to highly accurate in the 1960s. It concludes based on quantitative and qualitative analysis that learning from early failures led the intelligence community to achieve higher accuracy.