Immigration policy is one of the most contentious public policy issues in the United States today.  High-skilled immigrants represent an increasing share of the U.S. workforce, particularly in science and engineering fields. These immigrants affect economic growth, patterns of trade, education choices, and the earnings of workers with different types of skills. The chapters in this volume go beyond the traditional question of how the inflow of foreign workers affects native employment and earnings to explore effects on innovation and productivity, wage inequality across skill groups, the behavior of multinational firms, firm-level dynamics of entry and exit, and the nature of comparative advantage across countries.

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.

The papers in the sixteenth volume of the National Bureau of Economic Research’s Innovation Policy and the Economy offer insights into the changing landscape of innovation by highlighting recent developments in the financing of innovation and entrepreneurship and in the economics of innovation and intellectual property. The first chapter, by Ramana Nanda and Matthew Rhodes-Kropf, explores the process of experimentation in the context of financing of technology start-ups by venture capitalists. The second, by Yael Hochberg, also analyzes the role of entrepreneurial experimentation by systematically examining the rise of start-up accelerators. The third chapter, by Heidi Williams, studies the relationship between the strength of intellectual property rights and innovation. The fourth paper, by Fiona Scott Morton and Carl Shapiro discusses recent changes to the patent system and whether they align the rewards from intellectual property with the marginal contributions made by innovators and other stakeholders. The final chapter, by Karim Lakhani and Kevin Boudreau, focuses on the potential use of field innovation experiments and contests to inform innovation policy and management. Together, these essays continue to highlight the importance of economic theory and empirical analysis in innovation policy research.