This paper highlights some of the issues surrounding private sector participation (PSP) in the water supply sector and presents the results of the United Nations Research Institute for Social Development (UNRISD) research project, Social Policy, Regulation and Private Sector Involvement in Water Supply...Th[e] paper draws lessons from seven country studies: Brazil, Burkina Faso, Colombia, Great Britain, France, Hungary and Malaysia. All of these country studies show the shortcomings of PSP and how social policies are crucial in addressing the issues of access and affordability. The choice of social policies varies from country to country.