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

目前，室内滞留喷洒杀虫剂是减少疟疾等蚊媒人类疾病传播的最具成本效益的方法之一。然而，由于所使用的杀虫剂对环境和人类健康的潜在影响，IRS仍然是一个有争议的疟疾控制策略。传统上，二氯二苯基三氯乙烷(DDT)一直是IRS的首选杀虫剂。接触滴滴涕对人类的急性和慢性影响仍不确定。滴滴涕在生态系统中的广泛运输对环境造成的负面影响虽然仍不确定，但已得到更清楚的证明，但与明确确定的疟疾引起的死亡率和发病率的成本相比，这些影响的成本仍然难以评估。由于这些不确定性，政策制定者必须了解国税局有效减少疟疾传播的条件。特别是，人们普遍认为，85%的家庭覆盖率对于利用国税局实现显著、可持续的传输减少是必要的。如果有家庭层面的成本与允许国税局相关，那么人们可以期待一个家庭？S决定是否在他们的家里接受国税局将反映这些成本与减少疟疾的预期好处相比，后者在很大程度上由其他家庭的国税局决定。因此，这种类型的病媒控制策略可能会造成流行病外部性。这项研究将在乌干达古卢地区的4到6个境内流离失所者(IDP)营地使用600个家庭调查进行离散选择实验(DCES)，那里的疟疾负担特别高，在媒介控制方面非常重视国税局，以引起对接受替代国税局计划的偏好，从而(A)提高接受率和(B)评估流行病外部性的可能性。虽然其他经济学和流行病学研究已经产生了流行病学外部性的理论模型，但很少有应用工作来量化这种市场失灵在特定流行病或地方病背景下的福利影响。使用DCES来估计可用于反事实分析这种外部性的计量经济模型是一项重要的方法创新，这对发展、环境和健康经济学家来说是有意义的。布罗德影响目前，美国总统S疟疾倡议强调了IRS作为疟疾控制的主要战略的重要性，世界卫生组织(WHO)建议将滴滴涕作为IRS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，国税局的业务必须尽可能地减少疾病，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向合作战略，以提高IRS的疗效。因此，这项研究将通过在可能获得最大好处的地区更准确地针对设计良好的国税局计划来帮助制定政策。

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.