In order to support the conceptual work on private sector participation in water and sanitation infrastructure, a systematic review of country experiences has been carried out based on a common framework. It involves some 30 countries in Africa, Latin America and Asia/Pacific (Table 3.1) in several “dimensions” (Table 3.2). The resulting OECD Water at a Glance information base provides the basis for this section on regional trends and practices. A word of caution is necessary regarding the quality of data and particularly of time series. Changes in monitoring methods within countries and heterogeneity across country methodology may considerably alter the reliability of data and make comparisons over time and across countries difficult. Setting aside the potential measurement problems of absolute levels, broad trends still emerge from the information collected for Water at a Glance. The available data is also qualified and supported by qualitative information that allows for a better understanding of specific contexts.