The application of the contingent valuation method to environmental resources has been criticised on the grounds that individuals' responses are thought to be motivated by considerations not strictly relevant to economic valuation, thus leading to observed anomalies such as scope insensitivity. This study investigates the validity of contingent values in this context by reference to measures of attitude and of individuals' perceived motivation using a set of nested environmental goods (various levels of water quality improvement). Endorsement of the new ecological paradigm is found to be a good predictor of the perceived importance of certain motives for WTP (deriving from existence, anthropocentric intrinsic and bequest values), and of WTP for environmental improvement itself to the extent that these motives are perceived as important. The importance of these motives dominates that of others, such as those linked to private or social use value, and is positively associated with WTP, as is the extent of perceived personal responsibility. Moreover, all these relationships with WTP are reflected in an enhanced sensitivity of WTP to the scope of the good provided. However, WTP values are unaffected by the extent to which the individual feels under some general moral obligation to contribute to good causes. The findings support the internal validity of the WTP values elicited and suggest that the importance of motives deriving from certain nonuse values are more significant determinants of WTP than others, at least for the resource studied here.
Contingent valuation Motivation New ecological paradigm Nonuse value Warm glow