WILLINGNESS-TO-PAY FOR QUALITY IMPROVEMENTS - SHOULD REVEALED AND STATED PREFERENCE DATA BE COMBINED

In this article we propose theoretically consistent welfare measuremen t of use and nonuse values for an improvement in environmental duality with revealed and stated preference data. An analytical model based o n the comparative static analysis of the variation function that descr ibes the relationship between recreation demand and dichotomous choice contingent valuation models is estimated. Our results show that revea led and stated data should not be combined under the same assumed pref erence structure unless the two decisions imply the same change in beh avior induced by the quality change. In addition, our results indicate scope effects in willingness to pay measures estimated with stated pr eference data. (C) 1997 Academic Press.