報告書番号

Y93016

タイトル（和文）

わが国電気事業の垂直統合の経済性（投入要素比率固定の場合）

タイトル（英文）

ECONOMICS OF VERTICAL INTEGRATION OF JAPANESE ELECTRICITY INDUSTRY

概要 （図表や脚注は「報告書全文」に掲載しております）

イギリス型の垂直分割の是非に関しての最近の議論を踏まえて、わが国電気事業のパネル・データをもとにその費用の垂直構造の実証分析を行い、垂直統合の経済性の存在について検証した。この計測結果より以下の推測を行った。垂直統合の経済性の計測結果を発電量－送配電量の組み合わせで見ると、発電量が多く、送配電量が少ない操業形態以外の領域は、垂直統合の経済性が存在する領域である。発送配電一貫のわが国の９電力は、この垂直統合の経済性のある領域に位置しているので、垂直統合の経済性を享受しているものと考えられる。その結果、わが国電気事業の垂直分割を行えば、垂直統合の経済性を損なうという意味で社会的ロスが生じる可能性がある。

概要 （英文）

UNTIL RECENTLY, THE ELECTRIC POWER INDUSTRY WAS REGARDED AS A TYPICAL NATURAL MONOPOLISTIC INDUSTRY SUGGESTING THATUTILITIES IN THIS INDUSTRY SHOULD HAVE EXCLUSIVE FRANCHISES. HOWEVER, THIS ECONOMIC EFFICIENCY ARGUMENT WAS AMBIGUOUS BECAUSE SOME ECONOMISTSASSERTED ELECTRICITY HAD ALREADY EXHAUSTED SCALE ECONOMIES IN GENERATION. THEREFORE, CONVENTIONAL REGULATION, WHICH ALLOWED MONOPOLISITIC FRANCHISES AND VERTICAL INTEGRATION OF GENERATION, TRANSMISSION AND DISTRIBUTION, WAS CONTROVERSIAL. SOME INSISTED ON VERTICAL SEPARATION TO PROMOTE COMPETITION BETWEEN INCUMBENTS AND ENTRANTS IN THE GENERATION STAGE. OTHERS OPPOSED SEPARATION TO MAINTAIN ECONOMIES AVAILABLE BY VERTICALINTEGRATION. SINCE NEITHER OPINION HAD EMPIRICAL EVIDENCE IN THE JAPANESE CASE, EMPIRICAL STUDIES FOR ECONOMIES OF VERTICAL INTEGRATION ARE NEEDED TO ASSESS DESIRABLE REGULATORY ARRANGEMENTS. TO COMPENSATE FOR THIS LACK OF EMPIRICAL STUDIES, WE ESTIMATED JAPANESE ELECTRIC UTILITIESCOST FUNCTIONS AND CALCULATED THE ECONOMIES OF VERTICAL INTEGRATION USING PANEL DATA FOR A SAMPLE OF 32 ELECTRIC UTILITIES. WE DEMONSTRATED THAT THERE ARE ECONOMIES OF VERTICAL INTEGRATION IN BALANCING QUANTITIESBETWEEN GENERATION AND DISTRIBUTION IN JAPAN AND THAT A UTILITIES ENJOYED THESE ECONOMIES. MOREOVER, WE FOUND THAT ECONOMIES OF VERTICAL INTEGRATION DEPEND ON BOTH THE DEGREE OF DEMAND DENSITY AND LOAD FACTOR. THEREFORE, A VERTICAL SEPARATION POLICY MAY INCUR SOME LOSS OF EFFICIENCYIN THE JAPANESE ELECTRIC POWER INDUSTRY,

報告者

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