L’ANALISI COSTI-BENEFICI PER PROGETTI IN CAMPO AMBIENTALE. LA SCELTA DEL SAGGIO SOCIALE DI SCONTO

Abstract

The use of constant Social Discount Rates (SDR) in Cost-Benefit Analyses (CBA) has the effect of the excessive contraction of financial terms that are pro-gressively more distant in time. For this reason, the choice of SDR becomes crucial in the ex-ante evaluations of projects with inter-generational environmental implications, the benefits of which often affect generations different from those who bear the costs. A possible solution to this problem can come from the discounting of environmental components to an “ecological” discount rate less than the “economic” one, the latter useful to evaluate the financial cash flows. With this paper, we intend to define a probabilistic model to estimate the declining function of the two rates, the economic and the ecological, taking into account the correlation between consumption and environmental quality. The estimate conducted for Italy demonstrates the implications that such a model has on the entire environmental decision-making process.