1. Department of Economics, University of Chile, Santiago, Chile
2. National Superintendence of Sanitation Services and Peruvian University of Applied Sciences, Lima, Peru
3. National Superintendence of Sanitation Services and National University of San Marcos, Lima, Peru
4. National Superintendence of Sanitation Services and Scientific University of the South, Lima, Peru
5. Inter-American Development Bank, Washington, DC, USA