speci fi c unobservables in ηjv or child speci fi c unobservables in εijv are unlikely to be correlated with the migration network at the village level.

The PRHS 2001-02 includes a complete census of all village households which ascertained the household’s current migration status.<sup>23</sup> Using this, we construct a measure of the migration network for each village in our sample as the proportion of households in the village with a current migrant. While this census based measure of migrant networks is unlikely to be correlated with household speci fi c unobservables in ηjv, this is of course not the case for any number of village level unobservables which could well be correlated with both the propensity to migrate at the village level and village average child outcomes.<sup>24</sup> In order to deal with this problem, we need an instrument which varies within the village.

To get such an instrument we combine information on the migrant status of households with census information on their landholdings, to create a measure of the migrant network for different landholding groups in each village.<sup>25</sup> Since land is primarily inherited in rural Pakistan, concerns about changes in land distribution due to migration are unwarranted.<sup>26</sup> Inequalities in land ownership are also pervasive,<sup>27</sup> and access to land is an important marker of social and political status and is typically re fl ected in village settlement patterns. Given this, we expect that access to migrant networks may well vary signi fi cantly across landholding groups within a village. This gives us within village variation in the migrant probability of migration to the United States is higher for households living in Mexican communities which have greater experience with migration. Banerjee (1991) and Caces(1986) have shown the importance of networks in the rural-urban migration decision in the Indian and Philippine context respectively. Ilahi and Jafarey (1999), have shown the importance of extended family networks in fi nancing migration costs in Pakistan.

> 23 In the census,14% of households report a current migrant. This is signi fi cantly below the migration incidence we get from the household survey since the latter is not restricted to current migrants. It is worth noting that the number of households in the sample with a current migrant is just above 13%, as we would expect from the census.

> 24 It is important to note here that anthropometric growth measures re fl ect an amalgam of household and community inputs, including not just food intake and the ability to ward off infections, but also health care availability and quality, sanitation and public health campaigns. As such, there is often a weak correlation between household variables such as income, assets and education and levels of malnutrition. Alderman and Garcia (1994) point to this in the case of Pakistan, where levels of child malnutrition do not appear to be in line with reductions in poverty. They argue that community level variables and public health interventions may play a larger role in lowering malnutrition. It is therefore important in our context to examine wealth impact after controlling for community level unobservables.

> 25 Households with no land; households who own up to 15 acres of land; households who own between 16 and 50 acres; and those who own more than 50 acres.

> 26 In the PRHS 2001-02, for example, over 85% of land owned by sample households is reported as having been acquired via inheritance or as a gift from parents during their lifetime. We are thus not worried that more entrepreneurial households may acquire land, undertake higer levels of migration and invest more in their children..

> 27 The mean land gini at the village level is .75

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