Naturalization and immigrants' health
利用西班牙健康调查数据，研究发现入籍会加速移民健康水平向本地人收敛，机制是入籍后就业增加可能带来健康损耗。
The "healthy immigrant effect" refers to the well-documented fact that immigrants are healthier than natives upon arrival, but their health level converges to that of natives over time. Unfortunately, we know little about whether environmental, institutional, or selective return migration mechanisms are behind the convergence. In this paper, I test whether immigrants' naturalization influences health convergence speed. Using restricted-access Spanish health data from the National and European Health Surveys, I estimate the impact of naturalization on health by exploiting that naturalization is possible after 2 years of residence for immigrants from specific countries and after 10 years for all other immigrants. I find that naturalization worsens immigrants' health and thus accelerates the speed of convergence to natives' health. Increases in employment are potential mechanisms behind this effect.