On the Asymmetry of the Vagueness Band in Willingness to Pay Answers

The NOAA panel for Contingent Valuation opened up the question of the possibility of using trichotomous choice discrete formats in CV studies. In this paper we show how the trichotomous choice format can be used for testing the successfulness of the project definition in the questionnaire. We shall define the vagueness band around the ‘true’ outcome of the project to be valued and we allow it to be asymmetric. It is shown how this asymmetry can be modelled and estimated. We also show how these new models are generalisations of ordinary ordered probit/logit models. Copyright Kluwer Academic Publishers 1999