限界効用逓減

Can farmers sell agricultural products at the higher price by reduction of greenhouse gas （GHG）? Or can we find the decreasing marginal willingness to pay（MWTP）by the increasing reduction rate of GHG emission under the law of diminishing marginal utility? If so, what is the most beneficial way to deal with GHG emission for farmers? In order to answer these questions, we conducted an internet survey and got 2062 response. We used Ordered Probit Model to analyze consumer’s preference of rice produced by reduction of GHG emission and find the following results: the highest MWTP for reduction rate of GHG was 10.10 yen between 5 and 10 percent; 6.13 yen was between the 10 and 20 percent; 4.59 yen was between 20 and 50 percent; 0.89 yen was between 50 and 70 percent; MWTP, however, increased by up to 4.20 yen between 70 and 100 percent. Base on this result, we can say that consumers appreciate even a small reduction of GHG and then for farmers to start such activities from the small redaction is effective way when they sell environmental friendly agricultural products. Consumers also find another value for high reduction rate of GHG close to 100 percent. Additionally, other characteristics of consumers who appreciate reduction of GHG were young generation, high income, and more knowledge of farmer’s activities of GHG reduction.