US trade policy and public health: heterogeneous effects from the North American Free Trade Agreement.

OBJECTIVE: To investigate the causal link between the North American Free Trade Agreement (NAFTA) unrestricted sugar trade agreement signed in 2008 between the USA and Mexico and the diabetes prevalence across all fifty US states. DESIGN: A quasi-experimental research design to investigate the causal effect of the NAFTA unrestricted sugar trade agreement on diabetes prevalence. Our study utilises a comprehensive panel dataset spanning from 2000 to 2016, comprising 1054 observations. To conduct our analysis, we applied both the difference-in-differences and event-study methodologies. SETTING: All the states in the USA. PARTICIPANTS: The fifty states in the USA. RESULTS: After the enactment of the NAFTA sugar trade agreement between the USA and Mexico in 2008, most states witnessed an increase in diabetes prevalence. The annual impacts displayed significant variation among states, with percentage increases spanning from 0·50 to 2·28 %. CONCLUSIONS: States with a higher percentage of their population living below the poverty line, a larger Black resident population and a lower proportion of high school graduates had more significant increases in diabetes prevalence attributed to the NAFTA sugar trade agreement.

Estimating the unintended impact of the North American free trade agreement on U.S. public health.

The North American Free Trade Agreement (NAFTA) was introduced in 1994 between Canada, Mexico, and the United States to encourage trilateral trade. In 2008, an unrestricted reciprocal sugar trade agreement, was implemented between Mexico and the United States as part of NAFTA, which led to a significant decrease in the United States' sugar price. However, critics argue that free trade agreements that reduce trade barriers on products such as sugar threaten public health. This study uses the synthetic control method to investigate the causal impact of the unrestricted sugar trade agreement on sugar consumption and diabetes prevalence in the United States. First, we show that sugar consumption in the United States increased by an average of 16% annually after the agreement was signed, corresponding to 5240g per capita. Second, we show that the crude prevalence of diabetes increased by an average of 1% annually in the United States after the agreement was signed, with an increase of 1% and 2% for men and women, respectively. This unintended consequence of NAFTA has had an estimated economic cost of $324.37 million annually.