document a humped-shape relationship – emigration may increase with rising incomes in poor countries as households acquire the means to finance moving; but beyond some threshold level, the need to move declines (Martin and Taylor, 1996; Lucas, 2015). This nonlinear relationship can have different patterns; some micro studies of Indian villages suggest it was the very poor and the relatively well-off who moved; the former have little choice and nothing to lose, while the latter can afford to move (Connell et al., 1976; Mahapatro, 2014).

The empirical analysis based on the IHDS also shows that household size shares a nonlinear relationship with the migration decision. Analysis based on the IHDS shows that a smaller household is more likely to have a nonresident household member; but beyond a certain household size, migration is more likely to occur with an increase in the household size. The latter may be explained by the fact that beyond a threshold household size, smaller land holdings per capita mean that households find it difficult to continue to depend solely on agriculture (and have the greatest need for additional income) and are therefore more likely to send migrants to urban areas. The studies by Hay (1980), Nabi (1984) and Singh (1988) provide empirical support for this hypothesis.

Social group, which is another factor that is often alluded to in the literature on India, does not appear to have a statistically significant association with the migration decision in the analysis based on the IHDS. In the 2011-12 round of the IHDS, around one-fourth of the households with at least one nonresident member is classified as Scheduled Caste (SC) / Scheduled Tribe (ST). The regression analysis, however, does not show a statistically significant relationship between household social group and the presence of nonresident household members. This contrasts with the literature which argues that members of SC/ST households are less likely to migrate but may be explained by the fact that its effect is subsumed in the household consumption (income) variable. Dubey et al. (2004) outline two distinct groups of internal migrants in India – members of the higher caste households who generally migrate to attain a better standard of living and those from lower castes for whom migration often represents a struggle for survival.

The deterrent effect of distance upon migration is well established. The reasons underlying the observed negative correlation can range from transport costs to cultural alienation. The IHDS does not contain information on the destination of migrants; hence, a variable that captures distance could not be incorporated in the regression analysis. But the literature on India suggests that physical geographical distance has a robust negative association with internal migration across Indian districts and states (Kone et al., 2016; Government of India, 2017). While more distant locations would entail higher transport costs, these tend to be low in India – especially when lowerclass train fares are subsidized and riding on a bus roof without a ticket is not uncommon (Parida and Madheswaran, 2011). Evidence suggests that linguistic overlap between the destination and origin districts of migrants is positively associated with migration flows (Kone et al., 2016), where distant locations are less likely to possess the same language, religion and ethnicity (Lucas, 2015). The findings of the Government of India’s recent Economic Survey reinforce the importance of cultural similarities through a strong contiguity effect; controlling for distance, states that share common borders see about 65 percent more migration between them than states that do not share such a border. At the same time, the survey finds little evidence of language being a demonstrable barrier to the flow of people.

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