Ernest Ravenstein's Laws Of Migration

Ernest Ravenstein’s laws of migration states that migration is closely connected with "push-pull" factors such as low wages, high unemployment rates, and lack of health care and pull factors such as: high wages, low unemployment incline people towards leaving their original places of residence. In other words, the primary cause for migration is better external economic opportunities (Daugherty and Kammeyer 1995, Van den Berg H. 2009).
At present, the dominant theory in explaining causes of migration is the neoclassical theory with its underlying assumption that migration is stimulated primarily by rational economic considerations of relative benefits and costs, mostly financial but also psychological (Todaro and Smith, 2009). The theory has

The basic model that grew out of trade theory assumes perfect markets and a labour surplus in the traditional agricultural sector that is absorbed by the modern sector. The modern sector grows through capital accumulation and by poaching labour from the traditional sector (Lewis, 1954 and Ranis and Fei, 1961). Economic theory and empirical research have shown that the foundation of rural emigration to urban migration is the excess of the urban wage over the rural wage. Even other migration determinants such as distance, age and personal contacts only really reflect the fact that wage and productivity disparities

In these models migration occurs until wage equalisation has occurred. Migration is not completely risk-free because the migrant does not necessarily get a job upon arrival in the city. Rural-urban migration occurs as long as the expected real income differential is positive. Expected income is a function of the rigid, institutionally determined urban wages and the urban employment rate. Migration costs can be included. The employment rate is the probability of finding a job, i.e. being selected from the pool of labour, which increases over time, for example due to wider networks of the migrants. Migration thus increases if urban wages increase or the urban employment rate increases (ceteris paribus). It can be perfectly rational to migrate despite urban unemployment due to a positive expected income differential. Hagen-Zanker (2008) argued against this assumption as not having clear predictions and the significance of income differentials is undisputable in labour migration decision.
Increased rural emigration certainly makes the rural areas depopulated and this affects the rural economy in general and agriculture in particular, which is the main economic activity in those areas. Migration from the rural areas causes changes in resources (labour and land resources) in the rural