In the contingent valuation method for the valuation of public goods,
survey respondents are asked to indicate the amount they are willing t
o pay (WTP) for the provision of a good. We contrast economic and psyc
hological analyses of WTP and describe a study in which respondents in
dicated their WTP to prevent or to remedy threats to public health or
to the environment, attributed either to human or to natural causes. W
TP was significantly higher when the cause of a harm was human, though
the effect was not large. The means of WTP for 16 issues were highly
correlated with the means of other measures of attitude, including a s
imple rating of the importance of the threat. The responses are better
described as expressions of attitudes than as indications of economic
value, contrary to the assumptions of the contingent valuation method
.