Some notes on trichotomous choice discrete valuation

For some respondents, the bid offered by the dichotomous choice format used in the discrete choice technique can in fact be the true optimum. In this case the correct answer is neither yes or no, but indifferent. We shall show results from a trichotomous choice format and analyse whether it produces welfare measures with narrower confidence intervals than the dichotomous technique. Another well known problem in contingent valuation (CV) studies is that the volume of the good to be purchased from hypothetical markets is not, in many cases, defined in precise terms. We show how the trichotomous choice technique can be used to test for possible vagueness in the volume of the project to be valued.