How to Manage the Value of Drinking Water by Using Extension on the Contingent Valuation Method

International audience; This paper examines an explanatory policy in the management of drinking water in Tunisia. Indeed, the price variable, while is considered, in general way, as a confident indicator in the regulation of drinking water consumption, it seems to be insufficient since the management of drinking water is influenced by other set of variables such as: the revenue level of households, the consumption of bottled water, the alternative sources, the household size and, above all, the quality variable, which presents an enormous variability inter- and intra-regions. Through our study, we have shown, that the variation in willingness to pay (WTP) is essentially due to psychological and subjective consideration (the degree of importance of these variables in the scale of preferences of consumers).