A dialogue with country experts could be undertaken with the objective of suggesting some harmonisation in the aggregation and sampling methods, e.g. in terms of share of population covered, possible differentiation across geographical areas based on preidentified characteristics, etc. The method currently used (including in the OECD 2007-08 Survey) asks for a lot of data and relies on uncertain definitions. It might be easier to collect information about subsidies and transfers (from outside the water sector) received by utilities. These considerations could be organised in a checklist for policy makers, which would build on the analysis herein and on best practices in OECD and non-OECD countries.