Evaluation of public willingness to pay for marine litter management based on the correction of social desirability bias

[Objective] The purpose of this study was to explore the bias caused by social desirability effect in hypothetical market valuation methods and its correction, in order to improve the validity of valuation. The social desirability effect causes respondents to present themselves in a manner that conforms to social moral norms in order to obtain a sense of satisfaction, resulting in a bias in the valuation of resource, environmental, and material goods. [Methods] Based on a sample of 402 valid responses from Jiaozhou Bay, the inferred value method (IVM) was used in this study. By employing an indirect questioning approach, the study aimed to capture respondents’ actual preferences and willingness to pay, thereby correcting the bias caused by the social desirability effect. [Results] The use of the IVM, which involves asking respondents to speculate on others’ willingness to pay, effectively reduced the impact of social desirability bias on individual willingness to pay. This approach avoids overestimation of willingness to pay and enhances the accuracy of environmental economic valuation. Variables such as respondents’ age, estimated payment proportion, and approval of government waste management significantly influence willingness to pay. The average willingness to pay for public marine waste management estimated using the IVM was 179.17 yuan per year, while the valuation result using the traditional contingent valuation method was 275.87 yuan per year. The IVM provides more conservative valuation results, further validating its effectiveness in avoiding overestimation of willingness to pay. [Conclusion] The findings of this study can serve as a valuable empirical reference for the application of the inferred value method in the field of resource and environmental valuation in China. Additionally, they can provide some decision-making support for government efforts in managing marine waste pollution.