Migration is an age old process and it has often contributed positively to the progress of human society. Yet, when migration assumes the proportion of a population influx, its socio-economic and environmental impact in the receiving areas can be quite destabilizing. Assam, comprised of two fertile river valleys separated by a hill range in northeast India, has been receiving continual rounds of immigrations through her history. But the spurt in migration into the state in the decades following partition of India at independence form British rule caused serious social upheaval among the indigenous population. Though the frenzy of the days of anti-foreigner movement (1979-85) has died down, impact of influx of population, especially from the neighbouring countries, has remained a live issue in Assam. The need for a dispassionate assessment of the impact of that population influx induced the study resulting in the present monograph. The book should be of use to those who are concerned with migration process and its socio-economic implications and also to anyone interested in the contemporary socio-economic transition of the troubled territory of Northeast India.