Malaria, Productivity and Access to Treatment: Experimental Evidence from Nigeria

健康状况不佳对生产力和经济发展的后果被认为是严重的，但这种联系的严格证据基础很少。疟疾等病媒传播疾病直接影响到工人的健康，间接影响到工人的生产力和收入。在之前的工作中，我们使用随机设计，对尼日利亚一个大型甘蔗种植园的800名季节性甘蔗切割工人进行了一项治疗性疟疾治疗，估计其对收入、劳动力供应和生产力的平均治疗效果在统计上显着且很大。为了评估治疗效果，我们使用了个体工人生产率数据，这些数据来自计件工资制度，该制度提供了个体工人每日产出和劳动力供给的数据。在种植园建立了一个流动诊所，并在整个甘蔗收获季节使用外部确定的工人命令对工人进行检查和治疗。尽管平均治疗效果很大，但我们只估计了很小的，但统计上显著的意图，即只对劳动力供应进行治疗。这些结果解释了为什么公司不提供更广泛的疟疾检测和治疗。由于处理劳动力供给效应的意愿不大，企业雇佣更多的工人可能比投资于工人的医疗服务更具成本效益。但研究结果也提出了一个难题，即为什么工作人员不接受疟疾的预防性或治疗性治疗，而潜在的收益是巨大的。为了更好地了解工人在什么条件下会接受私人治疗，我们建议扩大我们的工作范围，以外部不同的价格提供疟疾检测和治疗，并估计其对医疗保健使用率和频率的影响，以及对工人生产力的影响。收集关于工人的社会网络和对疟疾感染风险的主观预期的更多信息，也将增进对私人保健和疟疾疾病保险需求的决定因素的了解。将在收获季节的第二部分提供治疗干预。在收获季节的第一部分，该研究将通过测量治疗对工人生产力和体力活动的影响来复制和扩展先前的方法。这将使我们对疟疾感染对一般体力活动的影响有更广泛的了解，并使我们能够对疟疾治疗对其他工作活动的潜在影响作出谨慎的推断。员工将在赛季开始时被告知，他们在赛季的第一部分（随机分配）获得免费治疗，但如果他们想要进一步获得治疗，则需要在第二部分支付费用。这种综合办法在为工人创造获得治疗的机会、确保他们认识到治疗的好处和尊重卫生保健提供的现实预算限制之间取得了平衡。

The consequences of ill health for productivity and economic development are presumed to be severe yet the rigorous evidence base for such a linkage is small. Vector borne diseases such as malaria cause direct impacts on the health and indirect impacts on the productivity and income of workers. In previous work, we have estimated statistically significant and large average treatment effects on earnings, labor supply and productivity of a curative malaria treatment using 800 seasonal cane cutting workers at a large sugarcane plantation in Nigeria using a randomized design. To estimate treatment effects, we use individual worker productivity data, derived from the piece rate wage system, which provides data on daily individual worker output and labor supply. A mobile health clinic was established on the plantation and used an exogenously determined ordering of workers to test and treat workers throughout the sugarcane harvest season. Despite large average treatment effects, we estimate only small, but statistically significant intent to treat effects exclusively on labor supply. These results present an explanation for why firms do not provide more extensive testing and treatment for malaria. Due to the small intent to treat labor supply effects, it is likely to be more cost-effective for firms to hire more workers than invest in health services for workers. But the results also present a puzzle as to why workers do not take up preventative or curative treatment for malaria, while the potential gains are large. To better understand under what conditions workers will take up private treatment, we propose to extend our work by offering access to malaria testing and treatment at exogenously varied prices and estimate its effect on take-up and frequency of health care, and their effects on worker productivity. Collecting additional information on workers' social networks and subjective expectations of the risk of malaria infection will also increase the understanding of the determinants of demand for private health care and insurance against illness from malaria. The access to treatment intervention will be offered during the second part of the harvest season. In the first part of the harvest season the study will replicate and extend the previous approach by measuring the effect of treatment on both worker productivity and physical activity. This will provide us with a broader insight of the effect of malaria infection on physical activity in general, and allow us to draw careful inference regarding the potential effects of malaria treatment on other work activities. Workers will be informed at the beginning of the season that they get a free treatment in the first part of the season (randomly allocated) but will need to pay in the second part if they want further access. This combined approach strikes a balance between creating access to treatment for the workers, making sure they realize the benefits of treatment, and respecting real life budget constraints of health care provision.