Although Bangladesh has absorbed several waves of immigrants since the onset of the twentieth century, the overall trend has been a steady emigration of people driven out by political and economic problems. Following the partition of British India in 1947, more than 3 million Hindus may have migrated from East Pakistan during the same period some 864,000 Muslim refugees immigrated to East Pakistan from India. The operation of the Pakistani military in East Pakistan in 1971 caused an estimated 8 to 10 million refugees to cross the border into India in one of the great mass movements of modern times (see Birth of Bangladesh , ch. 1). After the independence of Bangladesh, most of these refugees returned, although an undetermined number remained in India. After independence, Bangladesh received some 100,000 stranded Bangladeshis from former West Pakistan. About 600,000 non-Bengali Muslims, known as Biharis, who had declared their allegiance to Pakistan during the 1971 war, continued to reside in Bangladesh.

It has been reported that, beginning in 1974, thousands of Bangladeshis moved to the Indian state of Assam, and, in the 1980s, some tribal groups from the Chittagong Hills crossed into the Indian state of Tripura for political reasons, contributing to bilateral problems with India (see Foreign Policy , ch. 4 Insurgency in the Chittagong Hills , ch. 5). Bangladeshis also migrated to the Middle East and other regions, where a large number of skilled and unskilled persons found work (see table 6, Appendix Export Sectors , ch. 3). Bangladesh also lost some highly skilled members of the work force to Western Europe and North America.

Internal migration indicated several recognizable trends. Because of increasing population pressure, people in the 1980s were moving into areas of relatively light habitation in the Chittagong Hills and in parts of the Sundarbans previously considered marginally habitable. Agrarian distress caused some movement to urban areas, especially Dhaka. Because of the inhospitable urban environment and the lack of jobs, many newcomers returned at least temporarily to their villages, especially during the harvest season. Unemployment, however, was even higher in the countryside and was a long-term national problem in the mid-1980s (see table 7, Appendix).

Data as of September 1988