SUMMARY
The importance of the valuation of public goods is growing. In fact, only by determining the economic value of these assets is possible to determine the efficiency of the investments and of the maintenance. The problems in estimating the total economic value relate to two fundamental aspects: the choice and implementation of the more accurate evaluation methodology and the identification of the universe of users. In literature, in fact, the issue of the universe is often resolved by considering the number of potential users (be they the inhabitants of a city, a neighborhood, a street, etc..) and not the actual visitors. This leads to an underestimation or an overestimation of the use value of public goods. The objective of this research is to focus on this issue by proposing a specific methodological approach to correctly estimate the universe of the actual users of different urban green areas of Florence.