The paper presents a detailed comparative review of price/cost elasticity estimates published in a number of studies on multi-mode freight transport demands. It attempts to determine which factors could explain the wide diversity of estimates: data aggregation, diversity of markets, and...

This comment analyzes the demand model and method used by W. Wei and M. Hansen for computing the benefits of an airport capacity extension. The log-linear specification and coefficients of the demand function imply that the airport extension's positive effect on demand decreases with the volume...