Valuing hemlock woolly adelgid control in public forests: scope effects with attribute nonattendance.
Sensitivity to the scope of public good provision is an important indication of validity for the contingent valuation method. An online survey was administered to an opt-in nonprobability sample panel to estimate the willingness to pay to protect hemlock trees from a destructive invasive species on federal land in North Carolina. We collected survey responses from 907 North Carolina residents. We find evidence that attribute nonattendance (ANA) is a factor when testing for sensitivity to scope. When estimating the model with stated ANA, the ecologically and socially important scope coefficients become positive and statistically significant, with economically significant marginal willingness-to-pay estimates.