Differentiating use and nonuse values for coastal pond water quality improvements

This paper measures the benefits of water quality improvements in three coastal ponds on the island of Martha's Vineyard, Massachusetts, U.S.A. Use, option, and existence values were elicited from Martha's Vineyard property owners by the contingent valuation method. On average, more than half of the total benefits are attributed to existence value. Results from the Heckman selection model show that the exclusion of protest, as well as missing bids, does not cause significant bias in estimating respondents' willingness-to-pay. Socioeconomic characteristics are found to have distinctively different influences on use, option, and existence values. Different model parameters are likely to be estimated depending on which value categories are measured by a selected valuation technique. These findings emphasize the importance of nonuse values from water quality improvements and of socioeconomic characteristics for measuring different categories of values.