The Road to Healthier Diet: Benefits of the “Five Vertical and Seven Horizontal” National Trunk Highway System in China
Journal of Health Economics · 2026 · Xuyuan Zheng、Qinglin Lin、Gang Xie、Xiaohua Yu、Chengfang Liu
中文摘要
全球仍有数十亿人无法获得健康饮食,且高度集中于发展中国家的农村地区。本文利用“五纵七横”国道主干线系统(5V7H)——该国规模最大的高速公路网络,于2007年建成——的交错分批推进,考察重大交通投资如何改善农村家庭的膳食质量。采用交错双重差分设计,我们发现,5V7H 的接入使农村居民的膳食多样性得分(DDS)和中国健康饮食指数(CHEI)分别提高0.326分和2.197分。这些益处在子女较多、拥有冰箱或备餐者营养知识更丰富的家庭中更为突出,而在农业生产更多样化的家庭中则较弱。我们进一步表明,5V7H 的连通主要通过需求侧渠道改善农村居民的膳食质量,包括促进非农就业、提高家庭收入以及增强膳食素养。相比之下,供给侧渠道(如市场可达性改善或食品价格下降)的贡献较为有限。总体而言,我们的发现凸显了大规模交通基础设施在促进发展中国家农村地区向更健康饮食转型方面的益处。
Abstract
Billions of people worldwide still lack access to healthy diets, with a high concentration in rural areas of developing countries. This paper examines how major transportation investments can improve dietary quality among rural households, leveraging the staggered rollout of the “Five Vertical and Seven Horizontal” National Trunk Highway System (5V7H), the country’s largest expressway network completed by 2007. Using a staggered difference-in-differences design, we find that the 5V7H access increases the Dietary Diversity Score (DDS) and Chinese Healthy Eating Index (CHEI) of rural residents by 0.326 and 2.197 points, respectively. These benefits are more prominent among households with more children, access to refrigerators, or meal preparers with better nutrition knowledge, and less so among households with more diversified agricultural production. We further show that the 5V7H connection improves rural residents’ dietary quality primarily through demand-side channels, including promoting off-farm employment, raising household income, and enhancing dietary literacy. In contrast, the contributions of supply-side channels, such as improved market access or lower food prices, are modest. Overall, our findings highlight the benefits of large-scale transportation infrastructure in facilitating the transition to healthier diets in rural areas of developing countries.