A meta-approach to investigate the variance in transport cost elasticities: a cross-national European comparison

Results from past studies on transport elasticities show a large variance. The aim of this paper is to assess key factors that influence the sensitivity of travellers to transport costs in Europe, by carrying out a comparative analysis of the different elasticity values of demand for transport that are being used in some of the different Member States. Our empirical base are elasticity studies in four different European countries, namely Norway, Finland, The Netherlands and the UK. We are dealing here with a data set consisting of a limited number of observations (i.e. elasticity study results), thus we are facing a high level of uncertainty. Therefore, our in-depth analysis of these causes is based on a meta-analytic approach. Such an approach can be used to extract lessons from a limited set of different research studies. The specific meta-analytic method used is called rough set analysis. The paper starts with a description of the concept of transport price elasticity. It succeeds with a review of the literature. Then an in- depth analysis of possible causes of variances between elasticity values across the four European countries is presented based on rough set analysis. It appears that the emerging importance from the literature of the difference between aggregate, empirical-based research methods and the use of disaggregate choice models, as well as model assumptions, for explaining the variance in elasticity values across studies are largely supported by our rough set analysis. From this analytical approach it also appears that the country involved, the number of competitive modes and type of data collected have a relative strong explanatory power for the size of elasticities.