TESTING PART-WHOLE VALUATION EFFECTS IN CONTINGENT VALUATION OF INSTREAM FLOW PROTECTION

A review of studies of part-whole valuation effects in contingent valu ation highlights the difficulty of distinguishing part-whole bias from the effect of substitution among goods. A contingent valuation of ins tream flow preservation indicates that respondents with more informati on about substitutes were more sensitive in their valuations to the nu mber of rivers protected than were respondents with less information. These results, in combination with those of other studies of part-whol e valuation effects, suggest that contingent valuation researchers mus t design guidelines for deciding what information about substitutes sh ould be presented to respondents and how that information should be pr esented.