During the past decade, foreign participation in U.S. research and development--through acquisition of R&D-intensive businesses, links with universities, and other arrangements--has expanded rapidly. This emergence of foreign influence has drawn a mixed response--some regard the trend as a positive corollary to the expanding involvement of U.S.-owned companies in national markets abroad. Others consider it a net liability for Americans that often benefits foreign companies and their home economies at U.S. expense. There exists a large gap in expert and public understanding of the drivers, nature, and consequences of foreign participation in the nation's technology enterprise. This volume seeks to close this gap and reviews The nature of R&D activities and how they contribute to economic development. The causes, scope, and nature of foreign involvement in U.S.-based R&D activity and the associated costs, risks, benefits, and opportunities of this trend. The merits and liabilities of policies to regulate foreign R&D participation.