What is the legal and regulatory framework that is most conducive to institution building? What are the challenges of expanding water and sanitation from major urban centres into secondary towns and beyond? What criteria apply to decide whether to invest in optimal expansion or in reaching out to the most vulnerable and poorest? What is the optimal balance between centralized and decentralized approaches, both in technical terms (such as the choice between one major wastewater treatment plant or a grid of decentralized wastewater treatment plants) and in managerial terms? How can the rapid dissemination of new technologies be promoted in formal institutional set-ups? Keynote by Silver Mugisha