On the gap between payment card and closed-ended CVM-answers

The paper presents contingent valuation (CV) estimates of benefits provided by a proposed 'Kalkalpen' National Park in Austria. Although descriptive r esults of welfare measures are presented, the focus of the paper is on meth odological questions concerning the analysis of CV answers. Evidence is giv en regarding the difference between payment card (PC) answers and closed-en ded question formats. Based on different estimation models for CV questions substantial differences are found between closed-ended and payment card we lfare measures. On average PC-willingness to pay (WTP) measures are below t he closed-ended figures. Since the evaluation models are based on different premises in the calculation of WTP figures a more precise disclosure of th e underlying evaluation methods is required if different question formats a re compared to one another. Identical assumptions on the probability distri butions have to be assumed whenever open- and closed-ended CV welfare measu res are compared. Taking theoretical arguments into account the application of the closedended double-bounded Spike model that provides an average wel fare measure is recommended.