Measuring the environmental value of Saeng Island in Busan, Korea with allowing for zero values

This paper attempts to deal with zero willingness to pay (WTP) responses from dichotomous choice (DC) contingent valuation (CV) surveys. It also will apply a recently proposed one-and-one-half-bound (OOHB) question format in order to obtain an appropriate welfare measure such as the mean WTP. To this end, the spike model suggested by Kriström (1997) is adjusted and applied to modeling OOHB DC-CV data with zero WTP responses. The mean WTP per household was 2,716 Korean won per annum and the overall results show that the OOHB spike model outperforms the conventional OOHB model significantly.