Selectivity bias caused by protest responses in Contingent Valuation studies can be detected and corrected by means of … effect of protest responses would cause an upwards bias of the final estimates of WTP …

This study tests the hypothesis that hypothetical bias may not be related to value elicitation; rather it may be a … no evidence of hypothetical bias for three different commodity types (public good, private good, and publicly provided … support the hypothesis that the process of forming values in a homegrown setting may be a key contributor to hypothetical bias …

the dataset, and, if there is sample selection bias, they lead to biased estimates for the wtp measure. We propose a … survey design, and a sample selection model, that allows taking into account, and correcting, the possible bias due to … that sample selection models may present estimation problems because of the flatness of the likelihood function: in some …