稲作農家の農業共済制度下での均衡行動理論とリスク・リスポンス

Abstract

The rice insurance institution has had a long history in Japan since it was established in 1938. It has been a heavily subsidized multiple-risk crop insurance scheme, and the extent of subsidization has been increasing to an extreme level unitil recently. But, to the author's knowledge, comprehensive economic analysis of this institution has never been done, except one by the present author which is published as a chaper in a monograph on crop insurance by IFPRI and Johns Hopkins University Press in 1985. In that paper, the microeconomic framework for the analysis is not clarified. The first objective of the present paper is thus to describe algebraically and graphically the equilibrating behavior of rice farmers under the compulsory rice insurance institution applying the economic theory of uncertainty, in order to provide the author's previous paper with a theoretical foundation for the econometric analsis conducted there. In the previous paper, the basic approach was the positive risk response analysis of the rice farms. There have been only a few positive risk response studies in the world, and there, farmers' response to changes in risk has been saught, but the part of the total response caused by the changes in farmers' risk averseness has not been identified. Since the risk and the risk averseness are affected by different variables, and these veriables are affected by different policy instrument variables, it is, in the authors judgement, important from the point of view of policy analysis to eatimate separately the responses caused by changes in risk and by changes in risk averseness. In the previous paper, this separate estimation of risk response was tried using the part of insurance premium paid by farmers as a proxy variable for their risk averseness. The second obiective of the present paper it to support this approximation theoretically based on the microeconomic framework for the behavior of rice farms under the crop insuranceinstitution mentioned above.