For several decades, Senegal has faced inadequate water, sanitation, and
hygiene (WASH) facilities in households, contributing to persistent, high
levels of communicable diarrheal diseases. Unfortunately, the ideal WASH policy
where every household in Senegal installs WASH facilities is impossible due to
logistical and budgetary concerns. This work proposes to estimate an optimal
allocation rule of WASH facilities in Senegal by combining recent advances in
personalized medicine and partial interference in causal inference. Our
allocation rule helps public health officials in Senegal decide what fraction
of total households in a region should get WASH facilities based on block-level
and household-level characteristics. We characterize the excess risk of the
allocation rule and show that our rule outperforms other allocation policies in
Senegal