The main topic that we discuss in this paper}the valuation of environmental
public goods}is far from the core of economic discourse. It is an unusual case in
which some economists have proposed to use responses to hypothetical questions
as a measure of economic preference. In the contingent valuation method CVM.,
survey respondents are asked to indicate a stated willingness to pay SWTP. for
public goods, including goods from which they derive no personal benefit, such as
the continued existence of obscure species and the maintenance of pristine lakes in
inaccessible areas. The proponents of CVM have argued that properly elicited
statements of WTP reveal genuine economic preferences, to which consumer
theory applies Mitchell and Carson, 1989; Hoehn and Randall, 1987; Smith, 1992..