報告書番号

Y87017

タイトル（和文）

電気事業における規模の経済性

タイトル（英文）

ECOMOMIES OF SCALE IN JAPAN ELECTRIC UTILITIES

概要 （図表や脚注は「報告書全文」に掲載しております）

電気事業の規制緩和に関する分析の一環として規制緩和の根拠の一つとされる規模の経済性の計測を行った。計測にさいしては，トランスログ費用関数を推定し，それより規模の経済性を投入要素の変化に対する生産物の相対的な変化の割合と定義して計測した。今回の計測では，新たに詳細なデータベースを構築しそのデータにもとづいて，統合形態としての企業全体と発電部門とについてそれぞれ計測を行った。その結果，どちらについても規模の経済性は，減少傾向にあり，企業全体としては，まだ規模の経済性が存在しているものの，発電部門では，すでに規模の経済性が消滅しているという結果になっている。各企業別にも計測したが，ほぼ同様な結果であった。特に例外はあるものの大規模な企業では，より規模の経済性が減少している傾向にある。

概要 （英文）

THE PURPOSE OF THIS STUDY IS TO MEASURE SCALE ECONOMIES (SCE) FOR ELECTRIC UTILITIES IN JAPAN IN ORDER TO GET A INFORMATION ABOUT POLICY IMPLICATION OF DEREGULATION. WE GENERALLY DEFINE SCALE ECONOMIES IN TERMS OF RELATIVE INCREASE IN OUTPUT RESULTING FROM A PROPORTIONAL INCREASE IN ALL OUTPUT. IN THIS PAPER, WE ANALYZED FOLLOWING EACH 4 CASES, AGGREGATE FIRM LEVEL,AGGREGATE GENERATION LEVEL, DIS-AGGREGATE FIRM LEVEL AND DISAGGREGATE GENERATION LAVEL. AS ELECTRIC UTILITIES IN JAPAN ARE INTEGRATED WITH GENERATION, TRANSMISSION AND DISTRIBUTION, IT IS IMPORTANT THAT WHAT LEVEL WE NEED TO DEREGULATE. THE MAIN RESULTS ARE THE FOLLOWING: (1)SCE IS DECREASING FOR BOTH AGGREGATE FIRM LEVEL AND GENERATION LEVEL, AND FOR FORMER, IT HAS EXISTED IN RECENTYEARS BUT FOR LATTER, IT HAS NOT EXISTED SINCE SEVERAL YEARS. IT IS CAUSED MAINLY BY EFFECTS OF FUEL COST, THE IMPACT OF IT FOR SCE IS LARGERTHAN OTHER FACTOR IN OUR MODEL. (2)IN BOTH FIRM AND GENERATION LEVEL ON DIS-AGGREGATE CASES,THE TENDENCY OF RESULTS MEASURED BY SAME METHOD IS ALMOST SAME AS THE CASE OF AGGREGATE ONE. HOWEVER, THERE ARE SOME DIFFERENCES IN EACH ELECTRIC UTILITIES, BECAUSE THERE ARE DIFFERENCES IN SOME POINTS FOR EXAMPLE DEMAND DENSITY OR STRUCTURE OF POWER SYSTEM ETC.. AND LARGER THE SCALE OF UTILITIES SMALLER SCE IN RECENT YEARS. THEREFORE,WE MAY CONCLUDE THAT WE OUGHT TO DEREGULATE AT GENERATION LEVEL, BUT CONTINUE TO REGULATE AT FIRM LEVEL. HOWEVER IN OUR STUDY OF THIS TIME,THERE ARE SEVERAL FACTORS WHICH ARE ABSTRACTED,FOR EXAMPLE THE CHARACTER OF EACH FACTOR OR SO CALLED HEDONIC ATTRIBUTE, THUS WE WILL CONCLUDETHE NECESSITY OF REGULATION OR DEREGULATION FOR ELECTRIC POWER INDUSTRY IN JAPAN AT THE TIME WHEN WE GET MORE DETAIL INFORMATION.

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