Binary choice valuation studies with heterogeneous preferences regarding the program being valued

We investigate the effect of respondents' heterogeneous preferences regarding the good to be valued in binary-choice contingent valuationstudies. This is especially important when the valuation options give rise to both highly negative and highly positive attitudes. The survey design employs questionnaires which include separate items for willingness to favor and willingness to contribute in monetary terms tothe provision of the good. In light of our analysis, eliciting respondents' different preferences for the project first, without monetaryconsiderations, would improve the WTP estimates as welfare measures.Our results also suggest that nonparametric estimation could offer another solution for accounting for preference heterogeneity. Nonparametric estimation is less sensitive to those 'no' responses which are in fact not intended to reflect the respondents' WTP as such but merely to express their dislike for the good at issue. [ABSTRACT FROM AUTHOR]