مصرف برق در کشورهای G7: تجزیه و تحلیل هم انباشتگی پانل از کشش تقاضای برق مسکونی

This article applies recently developed panel unit root and panel cointegration techniques to estimate the long-run and short-run income and price elasticities for residential demand for electricity in G7 countries. The panel results indicate that in the long-run residential demand for electricity is price elastic and income inelastic. The study concludes that from an environmental perspective there is potential to use pricing policies in the G7 countries to curtail residential electricity demand, and thus curb carbon emissions, in the long run.

In 2005 the G7 countries together generated over 40% of the world's electricity and were major contributors to carbon dioxide emissions worldwide (BP, 2006). Growing concerns over the effects of greenhouse gas emissions for global warming have placed pressure on the world's leading economies to improve the efficiency of energy use. An initial response from the G7 to concerns about efficient electricity use was the formation of the E7, a nonprofit group comprised of nine leading electricity companies from the G7 in the wake of the Rio Summit in 1992 with the objective of promoting sustainable energy development.1 More recently, attention has been focused on obligations under the Kyoto Protocol which came into operation in February 2005. Under the Kyoto Protocol, the developed countries agreed to limit their greenhouse gas emissions relative to the levels emitted in 1990. While the United States has not ratified the treaty, it has also agreed to reduce emissions from its 1990 levels by 7% between 2008 and 2012. Economists have long argued that pricing policies are an effective instrument to improve the efficiency of energy use; however, the effectiveness of pricing policies to promote the efficient use of electricity depends on the price elasticity of demand for electricity. The objective of this article is to provide estimates of the income and price elasticities of G7 residential electricity demand. A methodological contribution of the study is that it employs a panel unit root and panel cointegration framework that takes into account the time series properties of the data. Recent studies have applied a panel unit root and panel cointegration framework to examine whether there is a long-run relationship between energy demand and real income for various groupings of countries (see Lee, 2005; Al-Iriani, 2006; Joyeux and Ripple, 2007), but this has not been done before in estimates of the residential electricity demand equation. There are a few studies that have estimated income and price elasticities for residential electricity within a panel framework utilizing pooled cross-sectional and time series state-level data within the United States (see e.g. Houthakker et al., 1974; Houthakker, 1980; Hsing, 1994). These studies, however, have not first tested whether the panel data are stationary, so the findings are potentially spurious. To test whether there is a long-run relationship between residential electricity demand and its determinants, the panel cointegration test of Pedroni (2004) is used which has the advantage that it allows for heterogeneity across countries. To estimate the long-run elasticities, we use ordinary least squares (OLS) as well as dynamic OLS (DOLS). The rest of the article is organized as follows. In the next section an overview of economic performance and electricity generation in the G7 is provided. In Section 3, we present a brief review of the existing literature. The empirical model to be estimated is discussed in Section 4. In Section 5 the econometric methodology employed is discussed. The penultimate section presents the empirical results, while the final section concludes.

The contribution of this study is to estimate income and price elasticities for residential demand for electricity for G7 countries using a panel cointegration framework. The main finding from the panel results is that the residential demand for electricity in the G7 countries is income inelastic and price elastic in the long-run. Electricity demand studies such as this have important practical implications. Firstly, reliable estimates of income and price elasticities of demand are important pieces of information for government in formulating policies for restructuring of the electricity sector and for the electricity companies when formulating demand management policies. Second, the price elasticity of demand contains useful information on the effectiveness of pricing policies as an instrument to promote the more efficient use of energy. The G7 countries as a whole generate almost one half of the world's electricity and are major contributors to carbon dioxide emissions. The relatively high magnitudes on the own price elasticities suggests potential to use pricing policies to curtail residential electricity demand in the long-run and that from an environmental perspective there is potential for the G7 countries to curtail residential electricity consumption and therefore carbon emissions, through the introduction of appropriate environmental policies such as the imposition of a carbon tax.