The ways in which migration and development have been linked in previous research in Third World settings are reviewed. Intercantonal migration in Costa Rica is analyzed, first in terms of a conventional model and then in terms of a paradigm of migration that focuses on place-to-place variations in development milieu. The results show there is spatial variation in the role of most variables and that these variations follow a reasonably consistent pattern with regard to development conditions. A series of maps graphically illustrates the importance of a spatial frame of reference.