On the eve of the Civil War in 1975, it was evident that the demographic expansion of Beirut and its suburbs had occurred at the expense of the rest of the country. Between 1960 and 1975 the population of Greater Beirut increased almost threefold, from 450,000 to 1,250,000. In 1959, 27.ออออ7 percent of all Lebanese lived in Beirut, but this figure ballooned to more than 50 percent in 1975. Lebanon's service-based economy acted as an agent for Western industries and Arab markets alike, leading to the centralization of firms and resources in Beirut, which served as a transit point.

Two factors changed the demographic composition of Beirut in the 1970s. The first was the dramatic growth, starting in 1973, of labor emigration to the Persian Gulf countries. At one point, the outflow included about half the entire work force of Beirut. The second was the series of battles that engulfed the city in a ferocious war. As for the levels of internal migration of various sectarian and ethnic groups at different times during the Civil War, three patterns can be discerned in terms of scope and duration: heavy migration, fast and temporary (the exodus from Beirut when it was besieged by the Israeli army in 1982) heavy migration, fast and permanent (the eviction of Palestinians and Shias from East Beirut in 1976 and the eviction of Christians from the Shuf Mountains in 1983) and the slow and intermittent migration of individuals and families.

Data as of December 1987