A NONPARAMETRIC TEST OF THE TRADITIONAL TRAVEL COST MODEL

The traditional travel cost model operates on the assumption that choi ces are made regarding the number of trips to various sites over an en tire recreation season. This paper uses actual recreation data to test the consistency of this model with postulates of rational economic ch oice as embodied in the axioms of revealed preference. The paper assum es consumer rationality and examines the effects of alternative trip p rices and model structures on the degree of consistency between them a nd the axioms of choice. Using tests developed by Varian and Tsur, the authors find that site choices at prices proxied by travel costs for most individuals in the sample violate the axioms. The violations are quite large when time costs, both in traveling and on-site, are omitte d from the prices. When they are included, violations are almost as nu merous, but not as large. The paper also examines demand heterogeneity by stratifying the sample and repeating the nonparametric tests. Thes e findings suggest caution be used in interpreting welfare measures de rived from traditional travel cost models, especially those that do no t include measures of time value. The authors' approach provides a met hod for screening travel cost data and preparing for model selection a nd estimation.