There are two explanations for labour migration. The first centres on the rational decision of an individual. An individual makes a decision, based on free will, to migrate to centres where there is a demand for labour. Migration is thus associated with urbanisation and modernisation, as well as with development. However, rational individual choice is not the only factor which affects labour migration in India. The second explanation emphasises the fact that capitalist development has always needed cheap labour. In this sense migration is analysed as a class phenomenon and uneven development is seen as the basic cause of labour migration.