We analyse the Social Return On Investment (SROI) as a form of evaluation that contributes to a wider analysis of investments by using some tools applied to the transport sector. In the first part of the paper, basic and advanced methodologies are outlined then, in the second part, they are discussed with the aim of giving emphasis to the difficulties of identifying all returns, to the need of valuing nonmarketable inputs and of addressing distributional issues in SROI analysis, particularly equity. The considerable presence of intangible effects bring about some problems of quantification, solved by SROI through the use of monetary units. If benefits are considered, it is evident that the share of benefits which do not have a market reference, in some projects, is of great importance. Thus project validity vitally depends on the evaluation of the effects such as noise, pollution and saving of time, and on the quality of SROI evaluation. One key point of the evaluation process, on which we focus in the third part, is the environmental impact of transport activity which is linked to the value of the land and the social implication of the willingness-to-pay principle through the use of empirical methods. We propose some novels in methodological terms to overcome such limits and to improve the obtainable valuated results. Final remarks conclude the paper.

References Yates, B., & Marra, M. (2017), Introduction: Social Return On Invetmsnt (SROI), Evaluation and Program Planning, Vol. 64. Write, S., Nelson, J.D., Cooper, J.M., Murphy, S. (2009), An evaluation of the transport to employment (T2E) scheme in Highland Scotland using social return on investment (SROI), Journal of Transport Geography, Vol. 17.