水田灌漑用水の経済評価: 仮想状況を設定した選択実験データの適用

抄録

Water pricing policy attracts great public interest for efficient water use in the world. To discuss water pricing, policy makers highly need the real value of water price and the price elasticity in the field. However, few studies measured these indexes in Asia as well as Japan. This paper evaluates the demand-side value of irrigation water for rice production at Toban Irrigation area, Hyogo Prefecture in Japan. The choice experiment data from contingent questionnaire survey were used in order to overcome data limitation on price and quantities used in the fields. Then, the price of irrigation water and the price elasticity of demand were derived by using estimations of the random parameter multinomial logit (RPML) models. The results showed that (i) the water pricing value evaluated by farmers was not high enough to compensate for the full-cost price including construction costs and maintenance costs of irrigation facilities, (ii) the derived demand for irrigation water with regard to water price was inelastic, and (iii) the statistical performance of the RPML model was superior to the conventional multinomial logit model. These results demonstrate usefulness of choice experiment data with contingent scenario for discussing water pricing policy.
JEL Classification: Q25, Q28, Q51