Mathematical Problems in Engineering

Research Article

Operational and Environmental Efficiencies of Japanese Electric Power Companies from 2003 to 2015: Influence of Market Reform and Fukushima Nuclear Power Accident

Table 1

Descriptive statistics on data set.


Production factors		Total assets	Total debts	Operating expenses	Total electricity sold	Total revenue	Total enterprise value	CO₂ emissions
Year	Statistics	Million JPY	Million JPY	Million JPY	MWh	Million JPY	Million JPY	CO₂-tons

2003	Avg.	4,465,605	3,561,477	1,379,535	91,905,433	1,593,677	3,981,324	39,414,444
	Max.	13,434,326	11,264,581	4,231,568	276,012,209	4,760,468	11,111,546	127,200,000
	Min.	1,342,188	995,523	385,961	25,624,361	441,839	1,182,516	10,290,000
	SD	3,635,846	3,063,621	1,146,055	75,710,121	1,292,679	3,040,231	34,141,577

2004	Avg.	4,342,806	3,392,945	1,392,252	95,359,384	1,628,767	3,845,022	39,459,311
	Max.	13,101,186	10,766,422	4,231,888	286,740,584	4,851,769	11,602,606	109,200,000
	Min.	1,305,437	952,755	390,704	26,874,339	460,958	1,162,507	9,790,000
	SD	3,522,907	2,909,690	1,145,031	78,585,385	1,318,702	3,169,047	29,286,607

2005	Avg.	4,357,095	3,326,625	1,434,394	97,245,806	1,651,795	4,015,784	40,798,889
	Max.	13,031,464	10,476,451	4,325,016	288,654,751	4,991,182	12,185,730	107,300,000
	Min.	1,404,443	1,001,007	414,205	27,966,251	469,966	1,240,030	10,830,000
	SD	3,491,916	2,810,633	1,163,742	79,008,615	1,351,239	3,290,078	28,645,106

2006	Avg.	4,296,315	3,224,315	1,473,627	98,005,219	1,679,884	4,052,379	39,927,222
	Max.	12,924,022	10,150,813	4,426,286	287,621,627	5,118,646	12,173,136	97,600,000
	Min.	1,380,425	995,246	422,134	28,160,564	476,019	1,297,458	10,360,000
	SD	3,457,160	2,714,267	1,194,735	78,585,812	1,384,016	3,280,331	26,478,384

2007	Avg.	4,302,088	3,291,292	1,619,652	101,339,239	1,739,205	3,891,591	45,541,887
	Max.	13,057,731	10,675,031	5,075,051	297,396,731	5,284,445	10,912,075	126,500,000
	Min.	1,364,394	1,023,718	440,847	29,268,787	469,020	1,266,823	11,460,000
	SD	3,486,517	2,856,396	1,375,140	81,092,176	1,430,928	2,903,728	33,163,979

2008	Avg.	4,311,563	3,378,009	1,762,906	97,939,836	1,838,667	3,725,786	43,103,333
	Max.	12,990,060	10,858,951	5,532,670	288,956,373	5,683,338	10,941,645	120,700,000
	Min.	1,347,486	1,001,935	489,626	28,154,209	515,749	1,259,239	10,850,000
	SD	3,462,285	2,906,011	1,495,492	78,602,889	1,536,831	2,887,395	31,444,105

2009	Avg.	4,231,181	3,291,930	1,487,044	94,559,728	1,630,706	3,580,642	38,311,111
	Max.	12,643,034	10,482,383	4,487,580	280,167,440	4,852,702	10,610,544	107,500,000
	Min.	1,320,236	998,380	421,412	27,175,151	463,738	1,255,051	10,160,000
	SD	3,377,277	2,807,766	1,209,665	76,153,985	1,313,912	2,801,966	28,721,640

2010	Avg.	4,468,755	3,640,106	1,553,555	99,877,397	1,718,837	3,409,217	40,972,556
	Max.	14,255,958	12,991,136	4,710,469	293,386,665	5,203,534	10,176,925	109,900,000
	Min.	1,316,794	1,006,916	434,950	29,100,358	486,139	1,083,602	9,500,000
	SD	3,835,032	3,531,110	1,270,858	79,865,659	1,408,952	2,713,838	29,854,442

2011	Avg.	4,676,075	4,043,128	1,796,601	94,707,593	2,027,739	2,912,639	47,976,287
	Max.	15,149,263	14,621,783	5,319,364	268,229,749	7,701,813	7,488,532	124,400,000
	Min.	1,313,106	1,030,068	474,225	28,444,127	492,984	1,025,457	15,628,000
	SD	4,097,329	4,001,908	1,448,806	73,139,772	2,122,533	1,979,356	32,595,518

2012	Avg.	4,686,176	4,127,626	1,927,074	93,808,443	1,952,830	2,873,832	53,321,281
	Max.	14,619,772	13,788,023	5,929,729	269,032,965	6,710,884	7,538,807	141,200,000
	Min.	1,318,731	1,057,315	470,347	27,410,102	482,227	900,594	18,642,990
	SD	3,947,264	3,745,077	1,614,906	73,271,192	1,839,130	2,013,272	36,174,926

2013	Avg.	4,680,315	4,110,129	2,016,494	93,442,828	2,280,060	3,196,480	53,299,740
	Max.	14,369,843	13,139,830	6,168,860	266,692,084	8,308,425	7,346,758	141,400,000
	Min.	1,334,456	1,065,950	479,019	27,214,049	500,791	1,027,942	17,703,434
	SD	3,867,108	3,553,853	1,691,582	72,633,115	2,294,840	1,974,398	36,424,436

2014	Avg.	4,594,658	3,980,654	2,046,801	90,607,479	2,262,950	3,123,444	50,483,713
	Max.	13,727,610	12,069,664	6,233,725	257,045,944	7,561,133	6,763,694	129,800,000
	Min.	1,338,671	1,062,094	476,976	26,392,144	516,067	1,043,817	17,830,000
	SD	3,665,241	3,253,602	1,720,854	69,806,163	2,078,961	1,826,821	33,317,439

2015	Avg.	4,473,834	3,803,205	1,828,779	87,712,054	2,102,094	3,223,828	47,548,264
	Max.	13,189,615	11,389,110	5,469,764	247,075,189	6,760,009	6,863,517	123,600,000
	Min.	1,348,660	1,076,308	464,658	25,754,603	496,984	1,083,685	17,230,000
	SD	3,487,096	3,030,281	1,474,398	66,920,036	1,842,257	1,865,051	31,440,075

Note. Avg., Max., and Min. stand for average, maximum, and minimum, respectively; Total assets, total debts, operating expenses, total revenue, and total enterprise value are measured in million Japanese Yen. Total sales volume is measured in megawatt hours (MWh). CO₂ emissions are measured in ton-CO₂.