It is argued that the spatial patterns of place-ties collectively held by potential metropolitan-to-nonmetropolitan migrants are broader than those held by potential nonmetropol itan-to-metropol itan migrants. Consistent with this argu ment, it is hypothesized that metropolitan migration fields are asymmetrical , i.e., out-migration fields are more cosmopolitan than in-migration fields for the period 1965-1 970 within the United States. The hypothesis is accepted generally, and the asymmetry is found to be greatest for the largest metropolitan areas, some of which were also experiencing net out-migration during the period. It is concluded that the micro-level concept of place-ties and the macro-level concept of migration fields are important inputs to the understanding of population redistribution patterns.