Consistency in mixed demand systems:: Contingent valuation and travel cost data

In contrast to previous literature, we propose a consistency test that does not impose any particular common functional form for the preference structure underlying the travel cost (TC) and contingent valuation (CV) models. We derive testable consistency conditions between TC and CV data in the context of mixed demand systems when valuing changes in environmental quality. These conditions are a subset of the rationality conditions. The proposed consistency tests are implemented combining TC and CV data. The empirical results show that it is possible to combine stated TC and CV but not revealed TC and CV data.