Data from a Thai campaign to register irregular migrants offer a rare opportunity to study
the labor market effects of immigration in a developing country. We use the registration
data, plus census and survey data on Thais, to study how immigration has affected wages,
employment, and domestic labor migration in Thailand. Essentially we test whether, all
else equal, Thais living in places with more immigrants have different labor market
outcomes from other Thais. We allow for endogenous migration, whereby immigrants are
disproportionately attracted to areas with higher wages, by using distance to the
Myanmar border as an instrument for migrant intensity. We allow for geographical
spillovers by estimating our model at two levels of geographical aggregation, and by
constructing a model with spatial lags. We also test whether Thais avoid migrating into
areas that have received more immigrants. Our results suggest that immigration has
reduced the wages of Thais. We find no evidence that immigration reduces employment,
or that it affects internal migration.