Just as group differentials are observed for mortality and fertility, distinct group differentials are also observed for migration, which are studied by comparing the characteristics of migrants with those who do not migrate but continue to stay in the place of origin and/or with those who live in the place of destination.

Researchers in demography and sociology are interested in the study of migration differentials from different point of view. For example, students of demography are interested in the age-sex patterns of migrants as they affect the age-sex structure of the place of origin and that of the place of destination.

The changes in the age-sex structure of migrants and non-migrants can affect the crude birth and death rates, the rates of labour force participation, the rates of school attendance, etc.

Other characteristics of migrants, such as marital status, levels of education, levels of fertility, occupational and ethnic composition, are of interest to various experts in different fields.


Sociologists are interested in the study of migration as it relates to problems of adjustments and assimilation of migrants. For such a study, the attributes of migrants and non-migrants have to be known.

The study of differential migration is also necessary for a building up of an understand of the factors which affect migration that is, why some per move while some others stay back or what distinguishes a people who migrates from one who does not.

It is also necessary for formulation of a migration theory or migration laws. Some & are interested in identifying universally valid migration different for the development of the principles of selectivity in migration.

Many researchers have pointed out that selectivity in migration depends to a certain extent, on the phase of migratory movement persons with certain attributes regarding sex, age, education attainment would tend to migrate in a particular phase.


For example, during the early state of urbanisation, there is usually tendency for rural males in the working age groups to move urban areas, while such males in urban areas move on metropolitan cities. During the later stages, however, migration becomes less selective and more representative of the population origin.

The important factors which determine selective migration and in turn migration differentials are age, sex, marital stat educational attainment and occupation.

Differential Migration by Age

The most firmly established generalisation in demography regarding differential migration that adolescents and young adult predominate among volume migrants, both with respect to internal and international migration.


Usually, among the migrants, there is a concentration of the belonging to the age groups 15-20 to 30-35. Zachariah found the in 1961; the age distribution of the migrants to Greater Bombay was distinctly different from that of the non-migrants.

Among the migrants, there was an excess of adolescents and young adult When the migrants were considered, 81.05 per cent belonged to the age group 15-59 (prime working age), the corresponding parental for the non-migrants being 37.27.

Again, whereas less than 10 per cent of the migrants were below the age of 10, 45 per cent of non-migrants were below that age. The greatest difference with thus evident in the youngest age group.

The age structure of the migrants was also found to differ from that of the general population of four places of origin, namely, Maharashtra, Gujarat, Uttar Pradesh and Bihar.


As far back as 1938, Dorothy Thomas, aft an exhaustive study of prevalent knowledge regarding migration arrived at the conclusion that persons in their teens, twenties as early thirties are more migratory than other groups.

Differential Migration by Sex

The phenomenon of selectivity of migrants is not as clear-cut as that of age selectively Regenstein, while stating his laws of migration, generalised in “Females appear to dominate among short-journey migrants.”

On the other hand, several studies have indicated that, in most of Asia and Africa, where the process of urbanisation is in its initial stage, males predominate when migration to urban areas is considered.


It was observed that in 1961, among the migrants to Greater Bombay, the males predominated. The ratio of males to 100 females among migrants was 181, whereas it was 111 for non-migrants.

This imbalance in the sex ratio among migrants became clear when the sex ratio of these migrants to Greater Bombay was compared with the sex ratio in the general population of the States from which these migrants were drawn.

It was concluded that males out-numbered females to a much greater extent in the migrant population than in the non-migrant population as well as in the population of the places of origin.

A completely different pattern, however, was observed for rural migration patterns. In a study conducted in Southern Maharashtra, it was found that rural migration was dominated by females, a pattern very common in India. Most of this female migration was due to marriage.


Thus it has been observed that, the selectivity with respect to sex is not the same in the rural-urban and rural-rural streams of migration in Indian conditions.

Studies, conducted in North America, Latin America, Europe and Oceania indicate that, among the migrants, females outnumber males.

All this research evidence suggests that the phenomenon of sex-selectivity in migration is very complex, for it depends mainly on the employment opportunities available to each sex and other considerations, such as migration due to marriage.

Differential Migration by Marital Status

Comparatively less information is available on migration differentials by marital status. The most serious difficulty in such a study is the lack of information on the marital status of migrants at the time of migration.

Socio-economic surveys conducted have revealed that a large proportion of Indian adult male migrants to cities are married and that they leave their families behind in the rural areas.

About half of the female migrant to cities migrated because of marriage. In Latin America, on the other hand, young married females moved to urban areas in search of employment.

Differential Migration by Educational Attainment

Educational attainment of migrants is an important item in the study of migration differentials or of the characteristics of migrants, for it is an indicator of their socio-economic status as well as their quality.

Migrants to Bombay and Calcutta are less educated than non-migrants at the place of destination, but they have a considerably higher average level of educational attainment the general population of the State from which they come.

In Greater Bombay, as a result of migration, the out-migrating are lose better educated persons, and the general level of education attainment of that area deteriorates.

On the other hand, as the educational level of the migrants is lower as compared to the migrants at the place of destination, the level of education attainment at that place also deteriorates.

In Greater Bombay, the level of educational attainment of migrants with respect to the : place of origin and their place of destination is lowered because of migration.

In a study conducted in Greater Bombay, when migration wives were categorised according to original residence in two group one with a rural background and the other with an urban background (that is those who had come from areas with a population of above 30,000 and above).

It was observed that the educational attainment of those with an urban background was slightly higher than that of the non-migrant wives and, better than that of migrant wives with a rural background.

In some Western countries, for example, the United States, among the net out- migrants from rural areas during the period 1940-1950 there were very highly educated persons at the same time there were those who had very low educational attainment.

In England and Wales, survey findings indicate that persons with at least a grammar school education were twice as mobile as those without such an education. Diverse observations have been made on the level of the educational attainment of migrants in many other studies as well.