High-skilled immigrant entrepreneurs contribute to U.S. economy by starting companies that create jobs and promote innovation. Much of our current understanding of the contribution of highly skilled entrepreneurs is based on popular accounts as available data sources do not allow for the identification of entrepreneurial firms in Science, Technology, Engineering, and Mathematics (STEM) fields. To provide empirical evidence this project will create new databases and new methods that will define high-skilled immigrant entrepreneurs in a systematic and rigorous manner. The project will then examine the choices faced by immigrants when deciding to start a new firm versus the decision to be employed by a larger corporation. Beyond the decision to start a firm the project will examine potential constraints that limit the growth and expansion of firms started by high-skilled immigrant entrepreneurs when compared to similar firms. The project contributes an understanding of the contribution of new firms started by highly skilled immigrants to the pace and direction of U.S. innovation and employment growth and makes suggestions to address policies that constrain the growth of these firms. <br/><br/>The project creates a longitudinal data platform to answer specific questions both at the person- and firm-level using micro-data on individuals and firms, including the Longitudinal Employer ? Household Dynamics (LEHD), Longitudinal Business Database (LBD), the Decennial Censuses and the American Community Surveys (ACS). The work covers a long time horizon (1991-2011), containing the most recent recession and initial recovery period. The specific research questions the project addresses include, the trends in the number, size, location and type of firms founded by immigrants; the number and quality of jobs created by those firms; the pathways leading immigrants into entrepreneurship; and, innovation patterns in the new start-ups. The LEHD based measures of immigrant entrepreneurs constructed under this project provide the basis for future research on this topic.