Temporal stability and transferability of models of willingness to pay for flood control and wetland conservation

This study investigates the temporal stability and transferability of dichotomous choice willingness to pay responses and their determinants from two large-scale contingent valuation surveys in the area of flood control and wetland conservation. The study considers a time period between surveys which is more than double that considered in previous test-retest analyses. Whereas such previous studies have reported stable values over relatively short time periods, the present study finds a statistically significant decrease in real willingness to pay over this more extended time period. Analyses of model transfer between the two survey periods indicate that models derived solely from economic-theoretic determinants pass transferability tests. However, expanding these models to include more ad hoc, transitory factors yields nontransferable models. This provides a guide for future analyses.