Environmental Engineering Reference
In-Depth Information
operators Limited
zone Non-linear
effects
Keywords Freight
traffic
Preference heterogeneity Retailers
1 Introduction
Cities have historically, but more so for modern cities, manifested a strong
dependence on freight transport systems to efficiently guarantee the net inflow of
goods and ensure the availability of the necessary resources to fuel economic and
urban growth. Local policy makers have intervened on the articulated contractual
relationships among agents so to achieve the desired policy objectives. The most
important agent-types in urban goods movement (UGM) are: retailers, transport
providers and own-account. Few are the studies that have explicitly investigated
the specific preferences and behavior of each of these agent-types (Stathopoulos
et al. 2012 ; Stathopoulos et al. 2011 ) notwithstanding the a priori relevance that is
ascribed to them (Ogden 1992 ). At the base of this research gap in this field one
can safely put the lack of appropriate data that is, in turn, linked to elicitation costs
and the low interest agent-types usually show when asked to participate in applied
research projects in this field. The capability policy interventions have in pro-
ducing the desired results is inextricably intertwined with the detailed knowledge
policy makers need to have concerning the most likely response the intervention
will produce given the extant regulatory, contractual and consuetudinal relation-
ships that characterize this sector in the given city where the policy is to be
implemented. In other words, we believe that one-size-fit-all policies, implying
policy transferability, are not easy to define nor to implement in accordance to
what has already been underlined by recent research (Stathopoulos et al. 2012 ).
The results reported and discussed are based on a data set derived from a
research conducted for a Volvo Research Foundation project (2009) that focused
on ex-ante policy mix evaluation for freight transport policies. The study con-
centrated on the freight Limited Traffic Zone (LTZ) in the city center of Rome.
The analysis takes advantage of the data set collected that explicitly differentiates
among three agent-types. The data include a wide range of information including
both specific respondent's and his/her company's characteristics as well as the
results of a Stated Ranking Exercise (SRE) where interviewees were asked to rank
alternative policy scenarios. The paper reports the results of two Multinomial
Logit model (MNL) specifications aimed at investigating the non-linear effects of
policy intervention on retailers' utility functions in a similar vein to Rotaris et al.
( 2012 ). 1 A comparison is performed, via willingness to pay (WTP), between the
potentially distorted scenario evaluations deriving from the assumption of linear
1 Non-linear effects on utility function can be also tested via self-stated attribute cutoff. Please
refers to Marcucci and Gatta ( 2011 ) for a detailed description and application.
Search WWH ::




Custom Search