In Stated Preference studies for the appraisal of environmental projects in poor countries or regions it often turns out that the stated willingness to pay of people for environmental improvements, which is used as measure of individual welfare changes, is very low. This is often interpreted as...

The Contingent Valuation Method (CVM) aims at the assessment of people's willingness to pay (WTP) for a public project. The sum of the individual WTPs is interpreted as the social benefits of the project under consideration and compared to the project costs. If the benefits exceed the costs the...