Behavioral Drivers or Economic Incentives? Toward a Better Understanding of Elicitation Effects in Stated Preference Studies

Survey-based welfare measures for public goods are often very sensitive to value elicitation methods, for example, whether the elicitation is framed as an up-or-down vote or an open-ended willingness-to-pay (WTP) question. Leading hypotheses for elicitation effects are tied to either behavioral factors (e.g., psychological cues) or differences in perceived economic incentives. Past research that emphasizes behavioral drivers does not precisely control economic incentives, potentially confounding inferences. We conduct an experiment that controls economic incentives through incentive-compatible elicitation methods and compare single binary choice, double-bounded binary choice, payment card, and open-ended response formats. Our experiment retains important field survey characteristics, including the valuation of an environmental public good with passive-use value. All formats elicit statistically indistinguishable WTP distributions, suggesting that behavioral factors may not be the primary drivers of elicitation effects. To the extent that our laboratory methods can be mirrored in the field, this offers a pathway for mitigating elicitation effects.