LIBRI DI ROMEO DANIELIS

The paper presents a methodology to estimate the potential demand for carsharing by university students. The methodology is based on three surveys: a paper-and-pencil questionnaire; a detailed computer-assisted personal interview, and a contingent valuation interview. The data collected are used to operationalize a model that estimates the generalized cost under alternative scenarios, with and without carsharing. A Monte Carlo simulation procedure is used to estimate the probability that a person would use carsharing. The methodology has been tested with students enrolled at the University of Trieste. The main finding is that, under the prevailing conditions, a quite large number of the sample students (32%) would benefit in terms of generalised cost from the use of carsharing if a private car were unavailable. The model is also used to perform scenario analysis.

Italian university students often attend a university located in a nearby city, and choose between commuting from their home town and living in the city where the university is located. The aim of this paper is to identify the factors that influence this choice. A conceptual framework is developed and an empirical investigation is performed analysing as driving factors the distance between home town and university town, rental costs, travel time, weekly frequency of attendance, course year in which the student is enrolled, student’s age and family income. According to the results obtained the critical isochrone varies from 65 to 75 km, and the monetary value of one hour of travel time is 13 euros. Finally, the impact of the policies currently implemented by the University of Trieste is analysed.

The paper provides an evaluation of the Ecopass road pricing scheme for the years 2008, 2009 and 2010. The term Ecopass conveys the stated political objective of the scheme: a PASS to improve the quality of the urban environment (ECO). The scheme has actually improved the air quality in Milan, although the recommended PM10 threshold is still exceeded for a larger number of days than that recommended by EU directives. This paper estimates the costs and benefits of the scheme three years after its implementation using the same methodology applied in Rotaris et al. (2010) for the year 2008. The results indicate that the benefits still exceed the costs, and by an increasing amount, but at an annual decreasing rate of improvement. The Ecopass scheme has proved beneficial, but it seems to have exhausted its potential: little further gains in air quality could be obtained via a fiscal incentive to improve the abatement technology of the vehicles. The new administration, elected in June 2011, was faced with the task of deciding whether to dismiss, maintain or change the Ecopass scheme. The prevailing idea coming from the Ecopass Commission and from the advocacy groups was to extend both the area of application and the number of classes subject to the charge. In November 2011 the new administration decided to substitute Ecopass with Area C, a policy based on a congestion charge which incorporates some environmental elements.

The paper illustrates a method to detect and estimate interaction effects in household decision-making and tests the representative member hypothesis by studying how preferences of single members influence family choices. We performed a stated choice experiment concerning hypothetical choices among alternative residential locations. We found that the rankings of the attributes for the family and for each member were the same. The estimated coefficients for each member were statistically different from family ones, which demonstrates the fallacy of the representative member hypothesis. We estimated single members’ relative power at the attribute level and extended a model developed in the literature to three-member groups.

Gli atti dell’VIII Riunione Scientifica del SIET evidenziano il ruolo centrale dei trasporti nel quadro dell’ampliamento dell’Unione Europea. Con lo scopo di perseguire obiettivi quali il risparmio energetico, la sicurezza dei trasporti, il contenimento degli effetti ambientali, il volume tratta problematiche legate all’omogeneizzazione organizzativa e normativa del settore e al ruolo dei trasporti e della logistica nelle realtà distrettuali. I contributi si focalizzano sulle criticità del trasporto locale e urbano e sulle ricadute che il sistema dei trasporti produce sull’ambiente.

Estimates of external costs of transport are quoted in important political and statistical documents. However, some theoretical and methodological aspects of the definition of external costs are still unclear. The paper discusses some of these issues. In the first part of the paper, having analysed the concept of external costs, and assessed its dependence on the institutional set up and on the assumption about altruism and information, the paper proposes a distinction between external costs and social costs. The former is associated with efficiency analysis, the latter with cost-efficiency analysis. The two concepts are then discussed with specific reference to external costs caused by transport activities. The second part of the paper reviews and discusses the main methodological uncertainties connected with the estimation of external cost of air pollution, congestion and accidents. It is argued that because of methodological and data constraints there appears to be insufficient knowledge on marginal external cost, whereas average social costs are better known.