A risk in the prices of fossil fuels is a major concern to importing countries of them. This study analyzes the risk of an increase in the cost for Japanese electric utility sector during the period 1978-2007 consider...A risk in the prices of fossil fuels is a major concern to importing countries of them. This study analyzes the risk of an increase in the cost for Japanese electric utility sector during the period 1978-2007 considering the uncertainty in the prices of fossil fuels. The mean-semivariance model, which uses an upper semivariance as an index of the risk, is adopted for the purpose. The result confirms that the semivariance is the better index of the risk than the variance. Furether, the semivariance is decomposed into two factors; the risk caused by price changes in an individual fossil fuel source and the risk caused by correlations among the changes in the prices of fossil fuel sources. The former has been kept at a low level as it appears to be easy to estimate, while the latter has not been maintained at the lowest level as it appears to be difficult to estimate. The Japanese electric utility sector followed the minimum-risk fossil fuel mix up until 2001, but discontinued the same post 2001.展开更多
文摘A risk in the prices of fossil fuels is a major concern to importing countries of them. This study analyzes the risk of an increase in the cost for Japanese electric utility sector during the period 1978-2007 considering the uncertainty in the prices of fossil fuels. The mean-semivariance model, which uses an upper semivariance as an index of the risk, is adopted for the purpose. The result confirms that the semivariance is the better index of the risk than the variance. Furether, the semivariance is decomposed into two factors; the risk caused by price changes in an individual fossil fuel source and the risk caused by correlations among the changes in the prices of fossil fuel sources. The former has been kept at a low level as it appears to be easy to estimate, while the latter has not been maintained at the lowest level as it appears to be difficult to estimate. The Japanese electric utility sector followed the minimum-risk fossil fuel mix up until 2001, but discontinued the same post 2001.
