Social security incentives, human capital investment and mobility of labor

Migration between countries with earnings-related and flat-rate pay-as-you-go social security systems may change human capital investments in both countries. The possibility of emigration boosts investments in human capital in the country with flat-rate benefits. Correspondingly, those expecting to migrate from the country with earnings-related benefits to a country with flat-rate benefits may reduce their investment in education. Allowing for migration may generate an intertemporal Pareto-improvement with cross-border transfers, and the contribution rates satisfying certain conditions. However, these conditions are not satisfied with those contribution rates that would arise if the governments maximize the welfare of their citizens without migration.