John Paul II asserts the right to migrate and this monograph presents a defense for this case. But the meaning of right employed in this defense is wholly distinct from that employed in the contemporary rights language of public policy debates. Rather, the meaning of right in Catholic natural law tradition is analogous to the right to property, and not to the right to life. Accordingly, the burdens of migration on host countries is fundamental to the analysis. Indeed most of the examinations of the right to migrate in Catholic social thought are conducted in the context of the economic motives for immigration public policy, as well as for emigration decisions on the part of individuals. This monograph thus presents an economic analysis of migration that is consistent with the Christian concern for the dignity of persons.