It has been difficult to open up the black box of knowledge production. We use unique international data on the publications, citations, and affiliations of mathematicians to examine the impact of a large post-1992 influx of Soviet mathematicians on the productivity of their American...

New York City is the hot spot of the COVID-19 pandemic in the United States. This paper merges information on the number of tests and the number of infections at the New York City zip code level with demographic and socioeconomic information from the decennial census and the American Community...

Over 11 million undocumented persons reside in the United States, and there has been a heated debate over the impact of legislative or executive efforts to regularize the status of this population. This paper examines the determinants of earnings for undocumented workers. Using newly developed...

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...

The Department of Homeland Security estimates that 11.4 million undocumented persons reside in the United States. Congress and President Obama are considering a number of proposals to regularize the status of the undocumented population and provide a “path to citizenship.” Any future change...

In May 1981, President François Mitterrand regularized the status of undocumented immigrant workers in France. The newly legalized immigrants represented 12 percent of the non-French workforce and about 1 percent of all workers. Employers have monopsony power over undocumented workers because...