Kentoku Funaki* and Yasoi Yasuda**

* DYNAX Urban Environment Research Institute
**Institute of Socio-Economic Planning, University of Tsukuba

+ Correspondence should be addressed to Kentoku Funaki
(Go Biru 3F 2-11-5 Nishishinbashi, Minato-Ku, Tokyo 105 Japan)

Abstract

The citizens of Gotemba city were asked whether they approved or disapproved of introducing a monetary charge policy for supermarket bags. Results showed that 78.1% approved of the policy. More over when we asked what would happen if a 5 yen charge were introduced, 16.9% answered that they would bring their own shopping bags. In the case of a 10 yen charge, 44.2% would bring their own. In the follow-up investigation into actual conditions, we found that 73.2% did indeed bring their own bags at the 5 yen charge policy, and 91.8% brought bags at the 10 yen rate. These results provided an interesting comparison of investigation by the questionnaire by CVM and the actual conditions. The difference between these at the 5 yen rate was 56.3% and at the 10 yen was 47.6%. That is to say, there is a "Hypothetical Bias" and the difference between an open-ended question and a closed-ended question was mainly observed with the CVM questionnaire answer being 50-60% less than actually observed.

Key words: hypothetical bias, CVM, WTP, supermarket bags, charge policy