China's Accession to the WTO as a Shock to Residents' Health-A Difference-in-Difference Approach.

The impact of regional trade shocks on population health has been a topic of interest in health economics in recent years. Unfortunately, there are few studies directly discussing the impact of regional trade shocks caused by China's WTO accession on the health of Chinese residents, which is essential to explore the connection between a country´s opening to international trade and the health of its residents. Taking China's accession to the WTO as a quasi-natural experiment, based on the micro individual samples of the China Health and Nutrition Survey (CHNS) from 1993 to 2011, this paper, for the first time, studies the impact of regional tariff uncertainty caused by China's accession to the WTO on the health of Chinese residents and its mechanisms by adopting the Difference-in-Difference (DID) model. The study finds that compared with the areas initially facing low tariff uncertainty, the areas with high initial tariff uncertainty have a greater negative impact on the health of residents after China acceded to WTO, which means that the trade shock caused damage to the health of residents. After a series of tests on the effectiveness and robustness of DID, this conclusion is still valid. The impact of the trade shock on residents' health varies with the type of residence, gender, and geographical location, and there is a nonlinear relationship. Further mechanism tests show that the trade shock has worsened the health status of residents through rural migration channels, working hours channels, and pollution emission channels. This study provides micro evidence for objectively evaluating the health effects of trade shock and has important implication for considering the health loss of Chinese residents in the process of trade liberalization.