In Thailand, as in other less developed countries, migration is assuming an increasingly important role in the dynamics of population growth and distribution. Concurrent with the recognition of migration's importance has been a growing awareness of the complexity of the process. A host of factors, including characteristics pertaining to the individual as well as to the places of origin and destination, determine who moves, when the move occurs, and to where. For example, research on Thailand (S. Goldstein, Prachuabmoh, and A. Goldstein, 1974) has shown that there are important occupational and educational differentials between the migrants on the one hand and the non-migrants at both origin and destination on the other. In general, migrants tend to be more educated than the rural population they leave behind; yet those moving to Bangkok are on the average less educated than the capital's natives. At the same time, migrants are disproportionally concentrated in service work, especially in Bangkok, where they are also particularly underrepresented among white collar workers. Moreover, migration is seldom a simple, one-step process; a substantial proportion of persons move several times. For some, these multiple moves involve a stepping-stone process from small to larger places; for others, the moves may be circular in character, involving return moves to place of origin.