National Bureau of Economic Research (NBER)Stanford University - School of Medicine, Environmental Health and WASH, University of California, Berkeley - Department of Agricultural & Resource Economics, Stanford University, Boston University, Stanford University, - Environmental Interventions Unit, Stanford University, Greentech Knowledge Solutions, Bangladesh Army University of Engineering and Technology (BAUET), Bangladesh, Stanford University, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), - Health Systems and Population Studies Division and Stanford University - Division of Infectious Diseases and Geographic Medicine