2007-08 NSSO survey. The IHDS therefore presents an appropriate sample to analyze internal migration for economic reasons, which, in turn, can promote the agglomeration of economic activity in productive locations.

Tracking the same households between 2004-05 and 2011-12, internal labor migration rates appear to have increased notably. In the IHDS, working-age male migrants (15 years or older) constituted 4.6 percent of the population in 2011-12, up from 1.6 percent in 2004-05; this indicates an increase in the stock of labor migrants from 16 million to 60 million over the seven-year period. This trend of increasing labor mobility is line with the Government of India’s recent Economic Survey, which estimates internal labor migration at between 5 million and 9 million annually – considerably higher than what has been previously estimated.

India’s low-income states dominated migration flows across and within states, especially the former. In terms of spatial movements, rural-urban migration was the dominant stream in both 2004-05 and 2011-12. Further, the share of those moving within and across states was almost evenly split, with the share of the latter increasing from 40 to 45 percent during the same period. The stock of “interstate” and “intrastate” migrants is negatively correlated with per capita state NSDP. Bihar and Uttar Pradesh had the largest stock of out-migrants moving to other states. Uttar Pradesh and Madhya Pradesh had the largest stock of out-migrants moving within states. In per capita terms, India’s seven low-income states had distinctly higher shares of internal migrants compared to richer states, with a few exceptions.

The absolute numbers of circular migrants, as measured in the IHDS, are much higher than previously documented estimates. The absolute number of short-term migrants – estimated at over 200 million in 2011-12 – is more than 10 times the 15.2 million short-term migrants in the 200708 NSSO household survey. These seasonal migrants are much more likely to be from socially disadvantaged groups and households with low levels of education. One-third of circular migrants were employed in the construction sector, with agriculture and informal sector jobs in manufacturing and services also being important. Circular migration flows appear to be mediated by contractors who perform the critical function of sourcing and recruiting workers.

The observed negative correlation between physical distance and migration can be explained by a range of factors from moving costs, through cultural alienation, to the availability of information. The analysis based on the IHDS showed that a household’s ability to finance sending out a resident member, as indicated by its level of consumption/income, is positively correlated with the probability of migration. The analysis also highlighted the potential importance of the availability of information through a positive association between exposure to mass media and the probability of households having migrant members.

The influence of social networks on internal migration in India cannot be emphasized enough. Community-based networks in destination areas increase the likelihood of an individual migrating to the same destination. At the same time, the literature also suggests that people are perhaps reluctant to migrate because they would lose access to social insurance provided by caste-based networks in source areas. Analysis based on the IHDS also shows that weaker ‘community bonds’ in addressing common issues or greater crime in source areas is associated with a lower probability 21