Department of Economics, Middlebury College, Middlebury, VT.
Am Econ Rev. 2017 May;107(5):516-21. doi: 10.1257/aer.p20171132.
It is estimated that about one quarter of the global disease burden in terms of healthy life years lost and about one quarter of all premature deaths can be attributed to modifiable environmental factors (Pruss-Ustun and Corvalan 2006). Three infectious diseases--diarrhea, respiratory infections, and malaria--account for the largest absolute burden in developing countries with children facing the greatest impacts. There is a growing body of evidence demonstrating the health burden of air and water pollution, as well as important productivity and income effects (see, for example, reviews of the literature in Pattanayak and Pfaff 2009 and Greenstone and Jack 2016). Studies that focus on the impacts of natural resource degradation are fewer. Notably, Garg (2016) provides the first causal estimates of the impact of sustained forest cover on reduced malarial incidence in Indonesia, demonstrating a large and previously understudied cost of forest cover loss. In this paper, we extend this new literature on the health impacts of environmental degradation by estimating the causal impact of forest loss on infectious disease incidence in young children using temporal and spatial variation in the last decade in Nigeria. Our estimation strategy involves geolinking a new high-resolution dataset of global forest change to child-level health data from the Nigeria Demographic and Health Surveys from 2008 and 2013. We find that forest loss significantly increases the incidence of malaria, though it does not affect the incidence of diarrhea and respiratory diseases. The impact of forest loss on malaria is large (one standard deviation of forest loss increases malaria incidence by around 4.5 percent in children under five) and the dynamic pattern of the impact suggests a temporary ecological disturbance consistent with findings in Garg (2016) and the tropical medicine literature.
据估计，全球范围内约有四分之一的健康寿命损失和四分之一的过早死亡可归因于可改变的环境因素（Pruss-Ustun 和 Corvalan，2006 年）。三种传染病——腹泻、呼吸道感染和疟疾——在发展中国家造成了最大的绝对负担，儿童受到的影响最大。越来越多的证据表明，空气污染和水污染对健康造成了负担，以及对生产力和收入的重要影响（例如，Pattanayak 和 Pfaff，2009 年和 Greenstone 和 Jack，2016 年的文献综述）。对自然资源退化影响的研究较少。值得注意的是，Garg（2016 年）首次提供了持续森林覆盖对印度尼西亚疟疾发病率降低的因果影响的估计，证明了森林覆盖损失的巨大且以前被低估的成本。在本文中，我们通过利用尼日利亚过去十年的时间和空间变化，扩展了环境退化对健康影响的新文献，估计了森林损失对幼儿传染病发病率的因果影响。我们的估计策略包括将全球森林变化的新高分辨率数据集与来自 2008 年和 2013 年尼日利亚人口与健康调查的儿童健康数据进行地理链接。我们发现森林损失显著增加了疟疾的发病率，尽管它不会影响腹泻和呼吸道疾病的发病率。森林损失对疟疾的影响很大（森林损失的一个标准差使五岁以下儿童的疟疾发病率增加了约 4.5%），影响的动态模式表明存在与 Garg（2016 年）和热带医学文献一致的临时生态干扰。
