Ran Song Publications

China’s accession to the WTO created new economic opportunities in certain cities. A shiftshare identification strategy shows that residents of adjacent rural areas migrated in and advanced economically. Longitudinal panel data on children reveals that their sons benefit, but counter-intuitively, daughters suffer worse mental and physical health, complete fewer years of schooling, and remain poor later in life. We explore why, and learn that hukou policy that restricts migrant children’s access to urban public schools is a factor. Triple difference research designs reveal that migrant parents become discontinuously more likely to leave daughters (but not sons) behind in rural areas exactly when and where hukou policy makes schooling more expensive. 69 million Chinese children are left behind in rural areas, and girls are harmed even when trade liberalization increases family income. Millions of poor Asian and African workers separate from their children in search of better livelihoods in richer countries, so this is a problem of global magnitude.

We quantify how pollution affects aggregate productivity and welfare in spatial equilibrium. We show that skilled workers in China emigrate away from polluted cities. These patterns are evident under various empirical specifications, such as when instrumenting for pollution using upwind power plants, or thermal inversions. Pollution changes the spatial distribution of skilled and unskilled workers, and wage returns by location. We quantify the loss in aggregate productivity due to this re-sorting by estimating a spatial equilibrium model. Counterfactual simulations show that reducing pollution increases productivity through spatial re-sorting by approximately as much as the direct health benefits of clean air.