Comparison of Mail and Telephone-Mail Contingent Valuation Surveys

A traditional mail and combined mail booklet with telephone interview mode are compared with respect to overall survey and individual item response rates, sample demographics, recreation participation behavior and willingness to pay (WTP) for improvement of wildlife and fisheries resources in California. WTP for five wildlife programs was measured with dichotomous choice CVM questions. The two survey modes yield statistically significant differences in overall survey response rate and response rate on dichotomous choice contingent valuation questions. Three of the five logit equations and mean willingness to pay amounts are statistically different, with the mail sample having nearly double the willingness to pay of the phone sample. Correcting for demographic, attitudinal and recreation activity participation differences between the samples results in only a slight narrowing of the mail and telephone estimates of willingness to pay.