This paper (2,04 MB) examines the experiences of private sector participation in the water supply and sanitation sector. The paper argues that publicly owned water utilities have not always been successful in both developed and developing economies. However, non-market failures in supplying water are much more severe in developing economies. On grounds of efficiency, public WSS services have remained wanting. Large proportions of the population remain with little or no access to public services, and the quality of services for those who receive them are often poor, characterised by frequent breakdowns and unreliable supply. The paper discusses that private sector participation has made more progress in high-income and middle-income countries, but has failed considerably in low-income developing countries. Success in wealthier countries is attributed to investment by private capital.