ADoctoral Dissertation Research in Economics: Estimating the Costs of an Epidemiological Externality from Malaria Control through Indoor Residual Spraying in Uganda

在住宅建筑物内表面进行室内残留喷洒（IRS）是目前减少疟疾等蚊媒人类疾病传播的最具成本效益的手段之一。然而，由于所使用的杀虫剂可能对环境和人类健康造成影响，滞留室内杀虫剂仍然是一种有争议的疟疾控制战略。传统上，二氯二苯三氯乙烷（DDT）一直是IRS的首选杀虫剂。人类接触滴滴涕的急性和慢性影响仍不确定。滴滴涕在生态系统中的广泛传播对环境的负面影响虽然仍不确定，但已得到更清楚的证明，然而，将这些影响的成本与明确确定的疟疾引起的死亡率和发病率的成本相比较，仍然难以评估。由于这些不确定性，政策制定者必须了解在何种条件下IRS能够有效减少疟疾传播。特别是，85%的家庭覆盖率被广泛认为是使用IRS实现显著、可持续减少传播的必要条件。如果允许国税局有家庭层面的成本，那么人们会期望一个家庭？决定是否接受国税局在家里是反映了这些成本与减少疟疾的好处相比,这在很大程度上取决于美国国税局决定的其他家庭。因此，这种类型的病媒控制策略有可能产生一种？流行病学外部性。本研究将采用离散选择实验（dce），在乌干达古卢地区的4至6个国内流离失所者（IDP）营地进行600个家庭调查。疟疾负担特别高且在病媒控制中高度强调室内滞留的地方？诱导对替代性IRS方案的接受偏好，从而(a)提高接受率和(b)评估流行病学外部性的可能性。虽然其他经济和流行病学研究已经产生了流行病学外部性的理论模型，但很少有应用工作量化这种市场失灵在特定流行病或地方病背景下对福利的影响。使用dce来估计可用于对这种外部性进行反事实分析的计量经济模型是一项重要的方法创新，这是发展、环境和健康经济学家感兴趣的。更广泛的影响目前，美国总统？世卫组织的疟疾倡议强调了滞留剂作为疟疾控制主要战略的重要性，世界卫生组织（世卫组织）建议将滴滴涕作为滞留剂中最具成本效益的杀虫剂。由于其成本和对人类健康和环境的不确定影响，必须最大限度地减少疾病，并反映目标家庭的知情偏好。此外，了解流行病学外部性的混淆潜力可以指出合作策略，以提高IRS的功效。因此，这项研究将有助于政策制定，使设计良好的IRS计划能够更精确地定位在可能实现最大利益的领域。

Indoor residual spraying (IRS) of insecticides on interior surfaces of residential structures is currently one of the most cost-effective means of reducing transmission of mosquito-borne human diseases such as malaria. However, IRS remains a controversial malaria control strategy because of the potential environmental and human health impacts of the insecticides utilized. Traditionally, Dichloro-Diphenyl-Trichloroethane (DDT) has been the preferred insecticide in IRS. The acute and chronic impacts of DDT exposure in humans remain uncertain. The negative environmental impacts from the widespread transport of DDT through ecosystems, while still uncertain, have been more clearly demonstrated, yet the costs of these impacts, when considered against clearly established costs of malaria-induced mortality and morbidity remain difficult to assess. Due to these uncertainties, policymakers must understand the conditions under which IRS is effective at reducing malaria transmission. In particular, a coverage rate of 85% of households is widely thought to be necessary to achieve significant, sustainable transmission reductions using IRS. If there are household-level costs associated with allowing IRS, then one would expect a household?s decision whether to accept IRS in their home to be a reflection of these costs as compared to the perceived benefits of malaria reduction, which are largely determined by the IRS decisions of other households. Thus this type of vector control strategy presents potential for an ?epidemiological externality.? This research will implement discrete choiceexperiments (DCEs) using 600 household surveys in 4 to 6 internally displaced person (IDP) camps in the Ugandan district of Gulu?where the malaria burden is particularly high and IRS has been heavily emphasized in vector control?to elicit preferences regarding the acceptance of alternative IRS programs and thereby (a) improve acceptance rates and (b) evaluate the potential for an epidemiological externality.Intellectual MeritWhile other economic and epidemiological research has produced theoretical models of epidemiological externalities, there is little applied work which quantifies the welfare impact of such a market failure in a specific epidemic or endemic context. The use of DCEs to estimate an econometric model that can be used for counterfactual analysis of such an externality is an important methodological innovation, which is of interest to development, environmental, and health economists.Broader ImpactsCurrently, the U.S. President?s Malaria Initiative has emphasized the importance of IRS as a major strategy for malaria control, and the World Health Organization (WHO) recommends DDT as the most cost-effective insecticide in IRS. Because of their costs and uncertain impacts on human health and the environment, it is important that IRS operations achieve the highest disease reduction possible and reflect the informed preferences of the targeted households. Moreover, understanding the confounding potential of epidemiological externalities can point to cooperative strategies to improve IRS efficacy. Thus, this research will aid policymaking by enabling a more precise targeting of well-designed IRS programs in areas where the most benefitis likely to be achieved.