Can Nutritional Label Use Influence Body Weight Outcomes?
利用美国国家健康与营养调查数据，通过倾向得分匹配方法，研究发现阅读营养信息对体重指数没有显著影响。
SUMMARY Many countries around the world have already mandated, or plan to mandate, the presence of nutrition related information on most pre‐packaged food products. Health advocates and lobbyists would like to see similar laws mandating nutrition information in the restaurant and fast‐food market as well. In fact, New York City has already taken a step forward and now requires all chain restaurants with 15 or more establishments anywhere in US to show calorie information on their menus and menu board. The benefits were estimated to be as much as 150,000 fewer obese New Yorkers over the next five years. The implied benefits of the presence of nutrition information are that consumers will be able to observe such information and then make informed (and hopefully healthier) food choices. In this study, we use the latest available dataset from the US National Health and Nutrition Examination Survey (2005–2006) to explore whether reading such nutrition information really has an effect on body weight outcomes. In order to deal with the inherent problem of cross‐sectional datasets, namely self‐selection, and the possible occurrence of reverse causality we use a propensity score matching approach to estimate causal treatment effects. We conducted a series of tests related to variable choice of the propensity score specification, quality of matching indicators, robustness checks, and sensitivity to unobserved heterogeneity, using Rosenbaum bounds to validate our propensity score exercise. Our results generally suggest that reading nutrition information does not affect body mass index. The implications of our findings are also discussed.