The paper by Jeffrey Grogger and Gordon H. Hanson examines the phenomena of positive selection and sorting in international migration, where more educated individuals are more likely to emigrate and to settle in countries with higher skill rewards. Using data on emigrant stocks by schooling level and source country in OECD destinations, the authors develop and estimate a model based on income maximization. The model predicts that migration is influenced by the absolute skill-related difference in earnings between the destination and source countries. Results show that migration increases with the skill-related earnings difference, and the relative stock of more-educated migrants is higher in destinations with greater skill-related earnings differences. The study also finds that post-tax earnings are a stronger correlate of migration than pre-tax earnings, and that language, distance, migration policy, historical relationships, and lagged migration also play roles. The authors conclude that the model successfully explains both positive selection and sorting, and provide insights into the mechanisms driving international migration.The paper by Jeffrey Grogger and Gordon H. Hanson examines the phenomena of positive selection and sorting in international migration, where more educated individuals are more likely to emigrate and to settle in countries with higher skill rewards. Using data on emigrant stocks by schooling level and source country in OECD destinations, the authors develop and estimate a model based on income maximization. The model predicts that migration is influenced by the absolute skill-related difference in earnings between the destination and source countries. Results show that migration increases with the skill-related earnings difference, and the relative stock of more-educated migrants is higher in destinations with greater skill-related earnings differences. The study also finds that post-tax earnings are a stronger correlate of migration than pre-tax earnings, and that language, distance, migration policy, historical relationships, and lagged migration also play roles. The authors conclude that the model successfully explains both positive selection and sorting, and provide insights into the mechanisms driving international migration.