While studying migration, it is important to find out who some people migrate and others do not. In other words, it is necessary to study the motivational factors associated with migratory movements.

Another important aspect of the study migration is the adjustment of the migrants to their new places o residence and their assimilation in the general stream of life, migration is affected by social, economic, political and situation- factors, this field of study is of interest to sociologists, society psychologists, economists as well as political scientists.

Because no generalisation about selectivity in migration is universally true, except for age selectivity, the study of motivation factors of migration becomes even more complex than the study o the behavioural and psychological aspects of the other two factor of population change, namely, fertility and mortality.

Hence out present theoretical and empirical knowledge of the phenomenon o migration is only very elementary. Many researches in migration are empirically oriented and contain only a factual description of migration streams and flows or, at the most, deal with the characteristics of migrants.


Due to the deficiencies in migration data and the problems inherent in them, demographers have devoted their attention mainly to methodological problems of the measurement of internal migration.

This explains why a majority of the studies on internal migration lack generalisation or at least attempt to build theories of the phenomenon of migration.

Those who have tried to generalise about migration phenomena, or have attempted to study the factors affecting internal migration movements, have adopted two distinctly different approaches.

The first approach is mainly situation-oriented in terms of push-and-pull factors, in the sense that it attempts to study the condition in the home which impel persons to move out of their place of origin on the one hand and the conditions and situation outside that attract persons on the other.


The second approach attempts to formulate empirical generalisations and describes patterns of migration, preferably in the form of mathematical models which are valid as universal laws.