Measuring International Skilled Migration: A New Database Controlling for Age of Entry Michel Beine, Frederic Docquier, and Hillel Rapoport Recent data on international migration of skilled workers define skilled migrants by education level without distinguishing whether they acquired their education in the home or the host country. Using these data and a simple gravity model to estimate the age-of-entry structure of the remaining 23 percent, alternative brain drain measures are proposed that exclude immigrants who arrived before ages 12, 18, and 22. the Belgian National Fund for Economic Research, professor of economics at the Universite Catholique de Louvain (Belgium), and a research fellow at the Institute for the Study of Labor (Bonn) and the Center for Research and Analysis of Migration at University College London; his email address is docquier ires.ucl.ac.be. Hillel Rapoport (corresponding author) is senior lecturer in economics at Bar-Ilan University, a member of EQUIPPE, Universites de Lille (EA CNRS 4018), and a research fellow at the Center for Research and Analysis of Migration at University College London; his email address is hillel mail.biu.ac.il. This article is part of the World Bank Migration and Development Program, which provided financial support. For permissions, please e-mail: journals.permissions oxfordjournals.org 249 250 THE WORLD BANK ECONOMIC REVIEW source country, which should consider as skilled emigrants only people who received post-secondary training in their home country. After zeros and a few suspicious observations were eliminated, 1,580 observations remained for each age threshold (1990 and 2000 included). Survey data are not available for many countries, and when they are (for example, in the EU Labor Force Survey and in the European Community Household Panel), they do not provide representative cross-sectional pictures of immigrants' characteristics. Included as origin country characteristics in Zk are i democracy indicators and measures of public expenditures on primary, secondary, and tertiary education. And included as host country characteristics in Wk f are indicators of social expenditures, education expenditures,3 and degree of openness to immigration. Bringing together the census data on age of entry, which represent 77 percent of skilled immigrants to the OECD, and the estimated structure computed using the results of the parsimonious model for the remaining 23 percent5 provides alternative measures of the brain drain from which skilled immigrants who arrived before a given age are excluded.