The fifteenth volume of Innovation Policy and the Economy is the first to focus on a single theme: high-skilled immigration to the United States. The first paper is the product of a long-term research effort on the impact of immigration to the United States of Russian mathematicians beginning around 1990 as the Soviet Union collapsed. The second paper describes how obtaining a degree from a US undergraduate university can open an important pathway for immigrants to participate in the US labor market in IT occupations. The third paper considers the changing nature of postdoctoral positions in science departments, which are disproportionately held by immigrant researchers. The fourth paper considers the role of US firms in high-skilled immigration. The last paper describes how strong growth in global scientific and technological knowledge production has reduced the share of world scientific activity in the United States, increased the immigrant proportion of scientists and engineers at US universities and firms, and fostered cross-border collaborations for US scientists.

William R. Kerr is professor at Harvard Business School and a research associate of the NBER. Joshua Lerner is the Jacob H. Schiff Professor of Investment Banking at Harvard Business School, with a joint appointment in the Finance and the Entrepreneurial Management Units, and a research associate and codirector of the Productivity, Innovation, and Entrepreneurship Program at the NBER. Scott Stern is the School of Management Distinguished Professor of Technological Innovation, Entrepreneurship, and Strategic Management at the Massachusetts Institute of Technology Sloan School of Management and a research associate and director of the Innovation Policy Working Group at the NBER.