مصرف زغال سنگ و بازبینی رشد اقتصادی

This paper revisits the causal relationship between coal consumption and real GDP for six major coal consuming countries for the period 1965–2005 within a vector autoregressive (VAR) framework by including capital and labour as additional variables. Applying a modified version of the Granger causality test due to Toda and Yamamoto [Toda HY, Yamamoto T. Statistical inference in vector autoregressions with possibly integrated process. J Econom 1995;66:225–50], we found a unidirectional causality running from coal consumption to economic growth in India and Japan while the opposite causality running from economic growth to coal consumption was found in China and South Korea. In contrast there was a bi-directional causality running between economic growth and coal consumption in South Africa and the United States. Variance decomposition analysis seems to confirm our Granger causality results. The policy implication is that measures adopted to mitigate the adverse effects of coal consumption may be taken without harming economic growth in China and South Korea. In contrast, for the remaining four countries conservation measures can harm economic growth.

Devising sectoral energy and environmental conservation strategies and policies to produce more secured energy to satisfy energy needs while reducing greenhouse gas (GHG) emissions is a major challenge facing many countries. As global demand for energy continues to increase, energy security concerns have become even more important [1]. Diversifying the sources of energy and finding a stable and a safe energy supply have became one of the main priorities of energy policy for many countries [2], [3] and [4]. The high degree of concentration of oil supply sources in the volatile region of the world where over 68% of oil and 67% of gas reserves are concentrated respectively in the Middle East and in Russia, clearly involves risks in terms of the reliability of the supply of energy needs for many energy importing countries [1]. After the 1973 oil crisis, supply security has become a primary concern for many oil-importing countries and has made the search for alternative source of cheap domestic energy supply as one of the main deriving forces behind the energy policy of many energy importing countries [2]. Coal plays a unique role in meeting the demand for secured energy, as it is globally the most abundant and economical of fossil fuels [1]. At current production levels, proven world coal reserves are estimated to last 147 years, in contrast to oil and gas which are estimated to last 41 and 63 years, respectively [5]. It is also projected that the greatest demand for fossil fuels will be coal, which will remain the second largest primary fuel source until 2030 [6]. In 2005, the major fossil fuels supplying total world energy were: oil 34.3%, coal 25.1% and gas 20.9% [1]. Coal is one of the major sources of energy for many countries. In 2005, coal accounted for 63.4% of total primary energy supply in China, 38.7% in India, 21.1% in Japan, 23.1% in South Korea, 72% in South Africa and 23.8% in the USA [6]. Furthermore, electricity from coal sources as percentage of total electricity generation accounted for 79% in China, 69% in India, 29% in Japan, 38% in Korea, 95% in South Africa and 51% in the USA [34]. While the combination of the several factors mentioned above makes coal a creditable source of energy, many believe that coal consumption is the major source of global warming as power plants that burn coal are major contributors to rising atmospheric concentrations of the greenhouse gas carbon dioxide (CO2) which contributes to global warming. Some even boldly claim that: “understanding the causes and curse of global warming is very simple. One word. Coal” [7].1 Despite the fact that coal consumption is an important source of energy for many countries, there are only few studies that have employed modern advanced in time series econometrics of cointegration and causality to test the relationship between coal consumption and economic growth [8]. Thus, the importance of coal in energy supply and energy security and also coal as a source of global warming necessitates not only further research but also the use of alternative testing methodologies. In a previous study on the causal relationship between coal consumption and economic growth [8] suggest that future research should investigate the above relationship using a more generalized multivariate system. In this paper, we do exactly that. It is against this backdrop that this paper attempts to fill the gap by examining the casual relationship between coal consumption and real GDP in six major coal consuming countries for the period 1965–2005 by including labour and capital as intermitting variables. We include capital and labour as additional variables as coal alone might not be strong enough to spur economic growth. Further, exclusion of a relevant variable(s) makes not only the estimates biased as well as inconsistent but also no causality in a bi-variate system can result from neglected variables [9]. It is possible that the introduction of a third or more variables in the causality framework may not only alter the direction of causality but also the magnitude of the estimates [10]. In addition, since a four-variable case incorporates more information than a bi-variate case, the causal inference drawn may be more reliable [10]. Thus the various bi-variate causality tests so far conducted may be invalid due to the omission of an important variable(s). In this paper the empirical evidence is carried out first by testing for causality using a modified version of the Granger causality test due to [11] which is valid regardless of whether a series is I(0), I(1) or I(2), non-cointegrated or cointegrated of any arbitrary order. Secondly, unlike previous studies, this paper attempts to quantify how much feedback exists from one series to the other using the recently developed generalized forecast error variance decomposition technique proposed by [12], which is invariant to the ordering of the variables. The rest of the paper is structured as follows. In Section 2 we make a brief review the empirical literature followed in Section 3 by the methodology used. The empirical evidence is presented in Section 4 while the summary and the concluding remarks are outlined in Section 5.

The aim of this paper was to revisit the causal relationship between coal consumption and real GDP for six major coal consuming countries for the period 1965–2005 within a vector autoregressive (VAR) framework by including capital and labour as additional variables to the coal-economic growth nexus. To do so, we applied two methodologies. First, we used a modified version of the Granger causality test, which is valid regardless of whether a series were I(0), I(1) or I(2), non-cointegrated or cointegrated of any arbitrary order. Secondly, we used the generalized variance decomposition analysis that is invariant to the ordering of the variables in the VAR system. The paper finds a unidirectional causality running from coal consumption to economic growth in India and Japan while the opposite causality running from economic growth to coal consumption was found in China and South Korea. In contrast, there was a bi-directional causality running between economic growth and coal consumption in South Africa and the United States. The variance decomposition analysis seems to support the Granger causality tests but the strength of this causality test was not relatively strong in China and India. The policy implication is that measures adopted to mitigate the adverse effects of coal consumption may be taken without harming economic growth in China and South Korea. In contrast, for the remaining four countries conservation measures can harm economic growth. Given the adverse effects of coal consumption, all countries should strive to control the use of coal and at the same time find ways of enhancing alternative energy sources that are safe, clean and cheap.