Grand Canyon white-water boating was used to address issues in contingent valuation of question ordering and respondent experience. Question-ordering effects were not identified for experienced boaters, but did occur in some estimates for less experienced boaters. An experience effect is further suggested if respondents value their actual white-water trips differently than written scenarios of trips. No effect was identified for experienced boaters, but a significant difference did occur for less experienced boaters. Significant differences for less experienced boaters suggest that respondent experience may play a role in value formation, resulting in survey instrument effects in valuation estimates.

Existence values for obscure resources should not be ruled out a priori because consumers have limited time and resources for information gathering. Furthermore, to the extent that environmental "good things" are highly substitutable, existence values must be cautiously interpreted when evaluating public choice alternatives, but similar concerns do not arise in damage assessments. Issues associated with adding up existence values across resources, high per unit values, and property rights in the existence of resources are also addressed.

In an excellent article from a recent issue of this journal, Sellar, Stoll and Chavas (1985) make a technical error which causes them to misstate their closed-ended estimates of willingness to pay. Truncation of the estimated cummulative distribution function must we made explicit in compution of willingness to pay.

Research dealing with the economic values of Great Lakes fish has focused on sport and commercial exploitation (consumptive use values). In this paper, we ask what other types of monetary values might be associated with Great Lakes fishery resources and examine how these other types of values (indirect use values and intrinsic values) relate to values derived from exploitation. We estimate a total value of $12,000,000 per year to Wisconsin taxpayers for preservation of striped shiners Notropis chrysocephalus, a Wisconsin endangered species that is resident in a tributary of Lake Michigan. For comparison, we estimate a total value of $28,000,000 per year for preservation of bald eagles Haliaeetus leucocephalus, also endangered in Wiconsin. In neither case was consumptive use a determinant of value. We also discuss the validity of the technique used to estimate these values. We conclude that intrinsic values for Great Lakes fish may be substantial. Future research should attempt to measure total values and not just values from exploitation.

In a recent study, Whitehead (2002) proposes incentive-incompatibility and starting-point-bias tests for iterative willingness-to-pay questions. We show that if restrictions associated with the nature of starting-point bias are not imposed on the ...