Exponential or Power Distance-Decay for Commuting? An Alternative Specification
Tinbergen Institute Discussion Paper No. TI 04-097/3
32 Pages Posted: 9 Sep 2004
Date Written: September 2004
In this paper we determine the effect of transport cost on commuting flows, on the basis of an analysis of home-to-work journeys between municipalities in Denmark. Special attention is given to a proper estimation method and the form of the distance-decay function. It appears that neither an exponential nor a power distance-decay function fits the data well. The specification of log trips as a (downwards) logistic function of log cost results in a better fit. We find that the cost elasticity of commuting reaches a value of -4 for distances around 24 km, while it is close to 0 for both very short and very long distances. Finally, we demonstrate that the choice of functional form for distance-decay can make an important difference for predictions concerning the effect of infrastructure improvements on commuting flows.
Keywords: Spatial interaction, distance-decay function, commuting, Denmark, estimation, heteroscedasticity
JEL Classification: C21, J61, R15, R23
Suggested Citation: Suggested Citation