The openness of the immigration policy toward developing countries is strongly debated in industrialized countries. In this paper we build an indicator of the "revealed" migration policy openness by computing the difference between the observed migration flows and the structural migration flows that depend on non-political factors of migration (economical, geographical and cultural factors). Using OECD's annual data on migrations, the indicator is built for 21 industrialized countries over the period from 1990 to 2006, allowing us to compare the restrictiveness / openness of policies between countries and over time.