مجموع عوامل رشد بهره وری انرژی در مناطق ژاپن

This article computes the energy productivity changes of regions in Japan using total-factor frameworks based on data envelopment analysis (DEA). Since the traditional DEA-Malmquist index cannot analyze changes in single-factor productivity changes under the total-factor framework, we apply a new index proposed by Hu and Chang [2009. Total-factor energy productivity growth of regions in China. Energy Policy, submitted for publication]: a total-factor energy productivity change index (TFEPI) that integrates the concept of the total-factor energy efficiency index into the Malmquist productivity index (MPI). Moreover, we separate TFEPI into change in relative energy efficiency, or the ‘catching up effect,’ and shift in the technology of energy use, or the ‘innovation effect.’ The data from 47 prefectures during the period of 1993–2003 are used to compute the TFEPI and its components for 4 kinds of energy. The TFEPI of electric power for commercial and industrial use changes −0.6% annually, which can be separated into a total-factor energy efficiency change of 0.2% and a technical change of −0.8%. The TFEPI for coal deteriorates by 1.0%/year, which is mostly caused by a decrease in relative energy efficiency change. We define and identify ‘innovators’ who cause the frontier to shift. Most regions identified as frontier shifters are located outside of Japan's four major industrial areas.

The first oil crisis hit the Japanese economy in 1973 and led to a drive for efficient energy use in Japan. As a result, Japan has achieved one of the highest levels of energy efficiency in the world. Energy conservation policy has been a crucial concern for Japan as a resource-poor country without a stable supply of energy. Moreover, Japan ratified the Kyoto protocol and must, by 2012, decrease its greenhouse gas emissions by 6% from its 1990 level. The Ministry of Environment (MOE) of Japan has proposed a carbon tax to mitigate carbon dioxide emissions since 2003. The proposed tax rate in 2003 was 3400 yen (approximately 29 US$ at the day's exchange rate) per ton of carbon contained in fossil fuel emissions, and, since 2004, it has been reduced to 2400 yen (approximately 22 US$ at the day's exchange rate). However, because of opposition from business interests, the MOE has failed to institute the carbon tax. Japan's carbon dioxide emissions from energy use have remained above the 1990 baseline and, in 2007, increased 15.0% above it. As Kasahara et al. (2007) suggested, a climate change tax combined with international emission trading might be a rational choice for Japan; however, in reality a climate change tax has been and will continue to be politically unacceptable. The Japanese government's plan depends on voluntary action to reduce energy use in industrial, commercial, and residential sectors, which seems to be unrealistic. In addition to Japan's obligation to implement the Kyoto mechanism including the international emission trading, improving energy efficiency or energy productivity per se has been the key issue for Japan's energy-environmental policy. However, the energy efficiency-enhancing policy may have two unintended consequences: First, improvements in energy efficiency may result in lower energy prices and in turn increased energy consumption. This is called the rebound effect which was first suggested by W.S. Jevons in 1865; however, this effect still remains debatable (recently, e.g., Hanley et al., 2009). Second, energy efficiency measures may not necessarily lead to reducing carbon emissions when Japan participates in international emissions trading schemes. In that case, the social cost of reducing carbon dioxide as well as the cap amount of carbon emissions will be different if Japan does not participate in these schemes. 1 Two well-known indicators are commonly used to study whether energy inputs are efficiently used. The first is energy intensity, which measures the amount of energy consumption for economic output produced in the economy. According to this kind of indicator, Japan is one of the world's leading countries in energy use. For example, if Japan's primary energy consumption (on a crude oil equivalent basis) per real GDP is taken as 1 in 2005, then that of the United States is 2.00, that of the United Kingdom is 1.35, that of France is 1.82, and that of Germany is 1.65.2 For example, at the industry level, if energy consumption per unit of production in the Japanese iron and steel industry is taken as 1, that of the United States is 1.25, that of the United Kingdom is 1.22, and that of Germany is 1.17.3 Moreover, if energy consumption per cement clinker in Japan is taken as 1, that of the United States is 1.77 and that of Western Europe is 1.30. The second indicator is energy efficiency (or energy productivity), defined as the economic output divided by the energy input (e.g., Berndt, 1990; Patterson, 1996; Han et al., 2007). Notice that although each indicator represents identical measures from different perspectives, we focus only on the application of energy efficiency and productivity in this paper. The conventional energy efficiency index introduced in Patterson (1996) is partial-factor energy productivity because it disregards the substitution among energy consumption and other factors (e.g., labor and capital stock). If energy consumption is evaluated in terms of partial-factor energy productivity, the end result is a misleading estimate (Hu and Wang, 2006; Hu and Kao, 2007; Han et al., 2007; Honma and Hu, 2008). For this reason, even though of the above international comparisons, it does not follow that energy efficiency in Japan is higher than in other developed countries. For example, Hu and Kao (2007) show that Japan is not the best performer in the APEC economy in 1991–2000 using a total-factor framework. This article evaluates the energy productivity change of regions in Japan with a total-factor framework. Under the traditional DEA-Malmquist index, one cannot evaluate the change in single-factor productivity under the total-factor framework. As a result, we use a new index, the total-factor energy productivity change index (TFEPI), which was proposed in Hu and Chang (2009). Following Hu and Chang (2009), we extend the work of Honma and Hu (2008) on total-factor energy efficiency (TFEE) to introduce a total-factor energy productivity index that integrates the concept of the total-factor energy efficiency index into the Malmquist productivity index (MPI). The MPI was first introduced by Caves et al. (1982) to measure total-factor productivity change by the ratio of the distance functions. Färe et al. (1994) broke down the MPI into efficiency change and technical change. They used data envelopment analysis (DEA), which is a nonparametric, linear programming method. To evaluate the TFEPI, we also use DEA. Moreover, we can decompose TFEPI into changes in relative energy efficiency (the catching up effect) and shifts in the technology of energy use (the innovation effect) under the total-factor framework. This study extends the panel dataset of Honma and Hu (2008) and analyzes prefecture-level data from 1993 to 2003. There are a single, aggregate output (real GDP) and 14 inputs in our DEA model, including 3 production factors (labor employment and real private and real public capital stocks), and 11 energy sources. To the best of our knowledge, no studies have attempted to assess changes in energy productivity for regions in Japan using a total-factor framework.4 The revised energy conservation law evaluates energy efficiency with respect to each apparatus, factory, and building from April 2009. Our results shed new light on Japan's energy productivity changes by examining those changes by region and energy type. The remainder of this paper is organized as follows: Section 2 introduces the proposed total-factor energy productivity index using the DEA approach. Section 3 interprets the data sources and describes the variables involved. Section 4 presents and discusses the empirical results in the case of Japan. Finally, Section 5 concludes the paper.

In this study, we used a new approach that combines the concept of TFEE and the Malmquist productivity index to assess energy productivity growth in regions in Japan between 1993 and 2003. We computed TFEPI for four representative energy sources in a multiple-input framework to avoid single-input bias. This enabled us to compute single-factor productivity under a total-factor framework. By separating out parts of TFEPI, we can identify both the catching up and innovation effects. The former effect indicates change in relative TFEE, and the latter effect indicates technical change. We can identify factors that reduce the energy efficiency of electric power for commercial and industrial use and coal. The TFEPI of electricity changed by −0.6% annually, which can be separated into a total-factor energy efficiency change of 0.2% and a technical change of −0.8%. The TFEPI for coal deteriorated 1.0%/year, which can be separated into a total-factor energy efficiency change of −1.1% and a technical change of 0.1%. From our findings, we conclude that deterioration in electricity efficiency is caused by a decrease in technical change, whereas that for coal is caused by a decrease in relative efficiency. The average annual net total-factor energy productivity changes of kerosene and heavy oil were 0.9% and 0.1%, respectively. Comparing TFEPI and consumption changes, we find that consumption of inefficient energy sources (electric power for commercial and industrial use and coal) has increased; and in contrast consumption of efficient sources (kerosene and heavy oil) has decreased. The best overall performers with respect to the TFEPIs for electric power for commercial and industrial use, kerosene, heavy oil, and coal were Hyogo, Okinawa, Nara, and Miyazaki, respectively; the worst performers were Shiga, Kanagawa, Ibaraki, and Kanagawa, respectively. We defined and identified areas as ‘innovators’ that have caused the frontier to shift. Many innovators are found in regions outside Japan's four major industrial areas. Saitama and Tokyo are exceptions and are often observed as innovators. We conclude that the regions that shift the frontier in Japan are those that are not developing mainly on the basis of manufacturing industry. Regions in the industrial areas should improve their energy use technology and adjust their industrial structures. In order to prevent depletion of natural resources and to meet the Kyoto target, Japan should improve its energy productivity. This new approach of total-factor energy productivity index serves to advance these purposes. The most important issue for future research is to examine what factors influence energy productivity. The relationships among energy price, per capita income, and energy productivity should be evaluated.