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

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.

This research project will identify the causal mechanism between improved health - via the reduction of malarial episodes - and its impact on worker productivity. By simultaneously measuring its impact on worker activity, it will also develop a method to draw inference regarding the impact of malaria beyond the study context. Finally, by offering access to malaria treatment and insurance, the study will estimate the conditional demand for malaria treatment.

The research outcomes have three potential impacts: both on a larger literature in public health and labor economics and on the policy of malaria eradication internationally.

Regarding the first area of impact, the study will assess the causal effect of health on productivity. Existing work on this is still scarce as it has been difficult to identify due to the dual causality between health and productivity. This study would isolate a single pathway and can control for other potential confounding unobservable factors such as worker motivation, ability, previous health investments, disease or morbidity history, and genetic characteristics, because the distribution of these unobservable characteristics would be identical between the treatment and control groups.

In a second area of impact, the study would produce more detailed information on the potential benefits of malaria reduction or eradication as a development strategy. These effects are currently imprecisely understood because of the lack of rigorous studies that take into account the implications of unobservable plantation, household and individual characteristics. This study will advance policy understanding in this regard.

In a third area, the study will provide constructive advice and ways forward on how to provide access to treatment for agricultural workers. It will allow estimation of workers' willingness to pay and hence provide concrete ways forward on how to offer access to malaria treatment and insurance in rural areas, which may help remove constraints on growth in agricultural productivity. By incorporating detailed social network information for each worker, a potentially important determinant of take-up of malaria testing and treatment will be formally integrated into the analysis.

The co-leadership and active involvement of the Centre for Research and Development at the Federal University of Technlogy at Yola, warrants that the findings will feed into both the Nigerian national academic and policy debates and maximizes its impact on policymaking, as the Centre has an exemplary track record in this area and its advice has been well absorbed by policymakers.

The project will also have an impact on the further development of the Centre's capacity with staff and students actively involved. We envisage that both masters and undergraduate students of the Parasite and Tropical Health Research unit, as well as laboratory science students will be part of the implementation team and participate in the analysis.

The proposal fits very well with the country malaria eradication strategy. The implementation of the on-going research was coordinated with the National Malaria Control Program within the Ministry of Health through a number of meetings, and was actively supported by the Director (then Dr Sofola).

Prof. Oladele Akogun is an integral part of this research. As Director of the Centre for Research and Development at the Federal University of Technology at Yola, Nigeria, he also actively engages a community of senior and junior researchers, as well as students in the research. Through the pilot, the project has already built capacity by actively involving masters, undergraduate and laboratory students in the implementation and analysis.

The research has also engaged Nigeria APSF, which is IFPRI's Nigeria Country Program which prefunded an initial feasibility study. There are also close contacts with The World Bank, USAID, DFID, and malaria experts in UK.