Using a spike model to deal with zero response data from double bounded dichotomous choice contingent valuation surveys

Modelling public behaviour with the data from double bounded dichotomous choice contingent valuation surveys is often complicated by zero willingness to pay (WTP) responses in the sample. To deal with the zero response data to obtain an appropriate welfare measure such as the mean and median WTP, the spike model suggested by Kriström (American Journal Agricultural Economics, 79, 1013-23, 1997) is used. The overall results indicate that the spike model outperforms the conventional model significantly.