Is the phone mightier than the virus? Cellphone access and epidemic containment efforts

This paper examines the impact of cellphone access on the containment of an epidemic. We study this question in the context of the 2014 Ebola Virus Disease (EVD) outbreak in Liberia. Combining novel data on cellphone towers and EVD cases, we estimate a high-resolution radio-wave propagation model that uses variations in terrain topography and the spatial distribution of cellphone towers to predict signal strength on the ground. We then employ a regression discontinuity design that compares villages at the margin of the signal strength threshold required for coverage. We find that having access to cellphone coverage leads to a 10.8 percentage point reduction in the likelihood that a village has an EVD case. Results from a novel survey collected following the epidemic suggest that this may be explained by cellphone access facilitating treatment provision. However, we cannot fully exclude that improving access to preventive care or information could have also contributed to containment.