Politiche pubbliche ed incentivi al risparmio idrico: il ruolo della tariffa

Public policies and water saving incentives: the role of tariff Integrated water service, which has undergone in recent years significant legislative revisions, can be analyzed in its complexity, related to the water industry, economic and technological characteristics of the different phases of production and distribution, to management issues of “water good” as a scarce resource and as merit good, and again to the possible forms of regulation and eventually privatization of the sector. Water economic regulation, in fact, clashes with articulated issues related to environmental, financial, infrastructural and tariff aspects. In this context, takes particular note, the role of the price: starting by the criticism of Full Cost Recovery Principle, on which is currently based water tariff analytical calculation, the work aims to determinate an integrated water tariff, as an instrument through which to build, in a decentralized way, the optimization of the reference system. After defining an optimal level of water consumption, in view of the preservation of the resource where it is not enough, an integrated water tariff must be capable of affecting the behavior of users, in an environmental sustainability perspective, as well as financial- economic one, and force them to realize optimal consumptions, assuming, therefore, itself, an instrumental role, not for the attainment of specific objectives, but in order to obtain optimal allocation of resources in a decentralized way. After describing the decision problem as definition of the optimal water tariff, which allows, starting from different supply systems, to induce water consumption considered optimal in a specific reference frame, in the model are compared four different scenarios. Model structure allows to observe all the effects that occur in the transition from one scenario to the other alternative hypothesized scenario; showing, therefore, how the integrated water tariff could induce users to achieve optimal water consumptions, as defined for each system considered. Starting from a formulation of the decision problem in terms of definition of an efficient human water consumption just for domestic use, which is implemented by an individual operator, who takes into account at the same time more than one aims, like environmental and water- saving one, we proceed to the determination of optimal level of consumption and to the calculation of the water integrated tariff which allows to achieve just that the default level. In this work, water integrated tariff represent, therefore, an instrument of demand management in order to achieve the efficient allocation of resources, pursuing at the same time socially relevant objectives assigned to the management. The objectives must be, therefore, allocated to the management, (thus affecting the calculation of the optimal consumption), and not to the tariffs, having those one the "general" role to transmit appropriate signals to users in order to induce them to realize optimal consumption