Social desirability bias in the environmental economic valuation: An inferred valuation approach

Environmental economic valuation allows to derive values from individuals? behaviour in hypothetical markets, but it is not exempt from certain biases. This work aims to evidence the existence of Social Desirability Bias (SDB) in the use of the stated preference method for environmental valuation. SDB is due to the consideration that, when interviewed, people provide responses to match the interviewer?s expectations or to be consistent with social norms. The Inferred Valuation Approach (IVA) was used to identify and quantify the social desirability bias in a choice experiment survey conducted to estimate the benefit of protecting a coastal Natura 2000 site. The results revealed the existence of a SDB that increases by 2.8-fold the benefits of the valued environmental assets. It is also found greater differences between use and non-use values when the IVA is used.