This study reports the findings from a year-long randomized evaluation assessing the impact of assigning 62 classrooms in Nigeria to receive either blocked or interleaved math problem sets. Blocked practice sessions focused on a single skill at a time. Interleaved problem sets alternated between...

This paper assesses whether delays in obtaining permanent residency status can explain recent declines in the share of Chinese and Indian PhD graduates from US STEM programs who remain in the US after their studies. We find that newly-binding limits on permanent visas for those from China and...

This paper experimentally investigates the effect of gender-based affirmative action (AA) on performance in the lab, focusing on a tournament environment. The tournament is based on GRE math questions commonly used in graduate school admission, and at which women are known to perform worse on...

There has been a proliferation of websites that warehouse instructional materials designed to be taught by teachers in a traditional classroom. While this new technology has revolutionized how most teachers plan their lessons, the potential benefits of this innovation are unknown. To present...

The largest and most important flow of scientific talent in the world is the migration of international students to the doctoral programs offered by universities in industrialized countries. This paper uses the opening of China in 1978 to estimate the causal effect of this flow on the...