Sex composition. Within developing countries, a growing share of rural-to-urban migrants are women, especially younger women (303). The trend reflects both the lack of jobs in rural areas and the increasing availability of jobs for women created by the labor-intensive manufacturing operations of multinational corporations. Also, many female migrants, particularly the young and single, work as domestics and in other service jobs available in large cities (165, 237).

Women often make up the majority of migrants from rural areas to the biggest cities, particularly in Latin America and, to a lesser degree, in East and Southeast Asia (27, 63, 140, 274, 316). Women also are beginning to comprise most of the flow to cities in Africa (192, 226)—a reversal of earlier patterns in the region (42, 104). In India, too, where men once dominated migration flows, rural-to-urban migration is becoming more female (140).

Concerning refugees, it has often been said that most are women and children (258). For instance, in mid-1995 the United Nations estimated that three-fourths of all refugees were women and their dependent children (308); in 1997 the United Nations Population Fund (UNFPA) stated that women and children make up 80% of refugees (302). A study of one refugee camp in Ghana reported that women and children made up over 70% of the total population of more than 13,500 people (80). These estimates are intended to stress the vulnerability of so many refugees, not necessarily to imply that most refugees are women.

In 1993 UNHCR began to make annual year-end estimates of the sex and age composition of refugee populations (258). The most recent report, covering data for 1993 to 1996, shows that the sex composition of refugee groups varies widely, even within a single country, and that it varies somewhat year by year (258).

The sex composition of refugees and displaced persons depends on the forces that have pushed people from their homes. For example, some refugee groups are mostly male soldiers. Other streams may be mostly women who have fled with their children for safety, while their husbands stayed behind to fight (258).

Among international migrants (not including refugees), men make up a slightly larger share—54%, according to the most recent estimate (293). Sending countries often restrict women's mobility, while in many receiving countries the demand has been predominately for men's labor (63). It is not possible to generalize further about the sex composition of international migration streams because groups of international migrants are so different from one another (48, 61, 63, 104, 140, 141).

Age. Like the populations of developing countries in general, most migrant populations are young. Migrants often are older than nonmigrants in the same area, however (84, 158, 236, 274). For example, in 19 of 22 countries studied using DHS data on urban women of reproductive age, a larger percentage of migrants than nonmigrants were over age 25.

Migration among women tends to peak at ages 15 to 24 (42, 104). Young women usually find it easier than older women to migrate because there are more jobs and because they have not yet married and established families. A second, smaller age peak occurs at around age 45, however. Women in their forties may be able to migrate more readily than women in their late 20s or 30s. Their family ties may have weakened after their children have grown, and they may also be widowed or divorced (104).

Among refugee groups, one estimate often used is that women of childbearing age constitute between 22% and 25% of the total (50). By comparison, in 25 countries with DHS data, the proportion of the total population between the ages of 15 and 49 ranged from 18% to 27% (23).

The United Nations has begun to provide information on the age composition of refugees (300). The coverage and the selection of age groupings are not detailed enough for planning purposes, however. The figures vary substantially from one year to the next. Moreover, summary data conceal large differences among refugee groups. In camps in Guinea-Bissau, for instance, 59% of refugees are children age 17 or younger. In camps in Benin, only 18% are children (300).

Marital status. The marital status of rural-to-urban migrant women varies widely by country, and there appears to be no pattern. In Senegal, Mali, Kenya, China, and many countries of Latin America, many migrants are single women (104, 122, 201, 338). In some African cities a substantial percentage of recent female migrants are unmarried or married but not living with their husbands (42). In other countries of Africa—Ghana and Tanzania, for example—married women are more likely than single women to migrate from the countryside to cities (104).

Unmarried migrant women often marry once they settle in new places. In 17 of 19 countries studied using DHS data, among women 20-to-24 years of age, higher percentages of female urban migrants than of urban natives were married. In some countries, however, the differences were small.