報告書番号

Y08020

タイトル（和文）

電力自由化と電気事業者の財務－米国電気事業者の実証分析－

タイトル（英文）

Electric Restructuring and Financial Performance of Electric Power Utilities An Empirical Study of the U.S. Utilities

概要 （図表や脚注は「報告書全文」に掲載しております）

米国では1992年のエネルギー政策法施行以来電力自由化が進展した。しかしその後2000年から2001年にかけて発生したカリフォルニア電力危機を契機に自由化の動きは停滞し，現在では新たに電力再編法を可決する州は見られない。そのような中，電気事業者の財務状況の悪化や債券格付け低下などが生じているが，それらと自由化にどのような関係があるのかは明らかにされていない。そのため，電力自由化と電気事業者財務の関係について，（1）自由化州と規制州の電気事業者の比較，および（2）自由化州の事業者の小売自由化前後の財務状況の比較を通じ，実証分析で明らかにする。

概要 （英文）

This report examined possible impacts of deregulation on financial performance of US electric power utilities. To this end, we first investigated changes in major financial indexes during the period from 1990 to 2007. Then we examined financial performance of utility firms using a discriminant analysis with logit model estimations. Our hypotheses were twofold. (1) The electric restructuring may affect financial performance of utility firms so that two groups, utilities in regulated states and those in deregulated states, are statistically distinguishable. The group difference may be explained by specific financial factors such as profitability and debt equity ratio. (2) The restructuring may affect financial performance of utility firms so that two groups, sample data after retail deregulation and those before the deregulation, are statistically distinguishable. The group difference is explained by specific financial factors such as profitability. From the estimated results of discriminant fuction, we found there were differences between those two sets of groups, where profitability was the most important factor to explain the difference. In addition, the performance difference between the two groups of firms before the restructuring remained unchanged even after the restructuring. Moreover, empirical findings implied that the deterioration of profitability might be partly attributed to the industry structure that tended to be more and more reliant on the power trading in wholesale power markets, where electricity prices were often higher than generation costs of vertically integrated utilities.

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