Keywords: Price Regulation; Water Services; Price Cap; Tariff's Indexation; Public Good.
Price regulation for Italian water's services is historically swinging between macroeconomic aims and sectoral or microeconomics different objectives. The effects on operating firms are obviously the worst: difficulties to plan long term investments, difficulties to organise activities, inefficiencies in financial optimization's process and so on. At the same time, political claims aiming to transform such an industrial service in a sort of Free Public Good are raising in Italy. In this paper the result of an analysis of historical evidences of public regulation and international experiences provide support for an idea of structural reform in such a price regulation problem: a «three parts Tariff» associated to different intertemporal indexations to get maximum efficiency to carry out all the engagements defining «Water Public Service».