Although the correlation between malaria and poverty is apparent, the nature of the linkages in terms of directions and mechanisms of causation is less so, and different methodologic approaches provide widely divergent perspectives concerning the impact of the disease. Certain macroeconomic studies find that in highly endemic countries, malaria may be responsible for reducing economic growth by more than one percentage point a year. Microeconomic studies, which aggregate the cost per case, find a considerably smaller impact, generally less than one percent of annual per capita gross domestic product. The large gap between these estimates suggests economic externalities associated with malaria that make the burden much greater than the sum of the costs of individual cases. Both the magnitude of the burden and the channels through which malaria affects reduces income are important for policymakers. We explore this gap, examining diverse mechanisms through which malaria can affect long-term economic development.