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.

环境经济评估允许从假设市场中个人的行为中获得价值，但它不能免于某些偏见。这项工作旨在证明在采用上述偏好方法进行环境评估时存在社会期望偏差（SDB）。SDB的考虑是，在接受访谈时，人们会提供与访谈者的期望相符或符合社会规范的回应。在选择实验调查中，使用推断估值方法（IVA）来识别和量化社会期望偏差，以估计保护沿海Natura 2000遗址的好处。结果表明，存在一个深发展银行，其价值是环保资产价值的2.8倍。