Survey response-related biases in contingent valuation: Concepts, remedies, and empirical application to valuing aquatic plant management

Sample nonresponse and selection biases that may occur in survey research s uch as contingent valuation applications are discussed and tested. Correcti on mechanisms for these types of biases are demonstrated. Results indicate the importance of testing and correcting for unit and item nonresponse bias in contingent valuation survey data. When sample nonresponse and selection bias go uncorrected, welfare measures map be overestimated or underestimat ed contributing to potential errors in resource policy and management decis ions.