تحلیل علیت مصرف دیزل و رشد اقتصادی در کامرون

This study examines the causal relationship between diesel consumption and economic growth in Cameroon by using a three-step modern time-series technique. Tests for unit roots, cointegration, and Granger-causality based on error correction model are employed on annual data covering the period 1975–2008. Empirical results of the study confirm the presence of a long-run equilibrium relationship between diesel consumption and economic growth. The error correction model shows that an estimated 1% increase in economic growth causes a rise in diesel consumption of 1.30% in the long-run. The overall results show that there exists bidirectional causality in the long-run relationship and no causality in the short-run relationship between diesel consumption and economic growth at the 5% level of significance. Thus, the energy policies in Cameroon should place priority on the discovery of new oil field and building capacity additions of the refinery to increase production of petroleum products, as this would propel the economic growth of the country.

Energy is the basic building block of economic development; it is driving wheel of the world's global economy and the foundation of modern society. It greatly contributes to human and economic development and well being of the society. Modern societies use huge amounts of energy for industries, services, housing and transport. We can name oil as example, which is now the most sold product, and diesel in particular, whose demand is greater than that of the other petroleum products in Cameroon (Cameroon Company of Petroleum Deposits, SCDP, 2009). It is omnipresent in virtually all sectors of energy activities in Cameroon. However, as the economy of African countries continues to grow, it is obvious to worry about the energy challenges that represent an obstacle to the continent's overall growth, especially the achievement of the millennium for development goals (Growth and Employment Strategy Paper, GESP, 2005). Although Africa is endowed with significant energy sources that remain unexploited in many cases, the continent is marked by the weakness of its energy services. Thus, energy conservation is assuredly dominated by two myths that first result, from a belief that social progress depends on the quantity of wealth produced and hence the amount of energy consumed. Secondly, from the idea that energy choices are the results of rational decision process that market mechanisms are likely to cause (Percebois, 1978). The relationship that exists between energy consumption and economic growth in a given country and at a given period of time rapidly varies with time and space due to many factors. Thus, the energy–economy relationship are usually mentioned (Diandy, 2009). The analysis of the causal relationship between energy consumption and economic growth is predominant in the literature to energy economics and has been subject to many empirical studies. Interest in establishing the direction of causality between energy consumption and economic growth was raised in the literature since the 1970s (Kraft and Kraft, 1978 and Akarca and Long, 1980). To date, except the global countries' studies (Esso, 2010, Akinlo, 2008, Wolde-Rufael, 2009, Wolde-Rufael, 2006 and Wolde-Rufael, 2005), no detailed study has been carried out on the causal relationship between energy or diesel consumption and economic growth in Cameroon. Does a causal relationship exist between diesel consumption and economic growth in Cameroon? Answers to this question are necessary to define and implement the appropriate energy development policies in Cameroon. We can spontaneously answer affirmatively to this question. It can be said before all experiments that a correlation exists between these two parameters, because energy as a whole is important for economic and social development. As a proof, the industrial revolution was possible due to the abundance of energy sources. From another perspective, the national economy exerts some influence on the energy consumption. The latter, through its evolution, determines the final energy demand (Spierer, 1982). The vast literature dealing with the same field as this work shows that researchers reached the following three conclusions: bidirectional causality, unidirectional causality and no causality between energy consumption and economic growth. Unidirectional causality results can be further divided into two categories: energy consumption causes economic growth and economic growth causes energy consumption. The purposes of this paper are therefore to describe the relationship between energy or diesel consumption and economic growth, and to investigate the long and short-run causality relationship between diesel consumption and economic growth in term of Gross Domestic Product (GDP) in Cameroon. The methods used in this study are a three-step approach. The first step is to check the properties (stationary and integration order) of two time series using the unit root test of Augmented Dickey-Fuller (1981). The second step involves the cointegration theory from the Johansen multivariate approach (Johansen, 1991, Johansen, 1988 and Johansen and Juselius, 1990), used to examine the long-run relationships between diesel consumption and economic growth. Finally, we establish the Granger-causality tests (Granger, 1969 and Granger and Weiss., 1983, Engle and Granger, 1987) within an error correction model in order to determine the direction of causality between diesel consumption and economic growth. The remainder of this paper is organized as follows: Section 2 provides a brief review of literature on causality studies related to energy consumption and economic growth. Section 3 gives an overview of the energy sector in Cameroon. In Section 4, the methodology adopted in the study is presented. We describe the data used in Section 5. Section 6 presents empirical results and the last section concludes the study.

This paper analyzes the causal relationship between diesel consumption and GDP in Cameroon over the period 1975–2008. Data series are obtained by the national institute in Cameroon. This study was done by using some developments in the econometrics of non-stationary time series including the cointegration theory. These times series techniques have permitted to explore the causal relationship between diesel consumption and economic growth in Cameroon. We began by testing the order of integration of series by the ADF unit root test. Then we tested the cointegration to determine the existence of a long-run relationship between variables. Finally we estimated the error correction model that aims at accounting in a same equation of a possible deviation from a long-run equilibrium and short-run adjustment dynamics of this equilibrium. The cointegration tests concluded the existence of ECT with the variables. This result is confirmed by Akinlo (2008), who was interested in 11 Sub-Saharan countries over the period 1980–2003, is also a cointegrating relationship between economic growth and energy consumption in Cameroon. The causality test within the error correction model shows that GDP Granger cause diesel consumption and diesel consumption Granger cause GDP at the 5% level. Thus, we concluded that there exist bidirectional causality in long-run and no causality in short-run relationship at the 5% level between diesel consumption and GDP. Our results are not in line with Esso (2010) and Akinlo (2008). They find no causality between energy consumption and economic growth. An interesting finding of the study illustrates that the vector error correction model analysis found that a one percent increase in GDP corresponds to a 1.3% rise in diesel consumption in the long term. This can be roughly translated as an energy intensity (percent increase of oil consumption/one percent increase of GDP) of 1.3 for the nation. In Cameroon, an economic policy aimed at improving energy or diesel supply will inevitably have a positive impact on economic growth. Hence, energy is a stimulus to economic growth and feedback. Moreover, an economic growth will be according to forecasts of the Ministry of Economy, Planning and Regional Development focus on increasing diesel consumption in the industrial sector, and consequently, the economic and social development of Cameroon. In addition, Rosellini (2005) shows that the main challenge for the oil countries of Central Africa are the maximization of their oil resources for the development and well-being of the population. This is in agreement with the statistical results. However, field surveys (Ministry of Energy and Water resources, 2011) have shown that a reduction in diesel consumption or energy to be efficient (the energy intensities in the countries where energy is utilized more efficiently are close to 1.0 or lower) is not a conceivable option in Cameroon. For, according to the SIE-Cameroon (2010), Cameroon's population still has a difficult access to the consumption of energy (except for firewood). Thus, the average energy consumption per capita in 2008 was 0.30 toe and it is strongly dominated by firewood consumption which is (very inefficient for the economy of Cameroon) at 73%. This energy consumption is lower than the African (0.48 toe per capita) and world (1.25 toe per capita) average. This is a tangible proof that Cameroon has not yet attained self-sufficiency. Hence by making modern energy (besides firewood) available to everyone could help reduce not only poverty but also improve the leaving standard in Cameroon. The government should adopt policies to ensure that the diesel consumption used in the country turns into a full benefit of the nation's economy improvement. Ultimately, energy supply is inadequate and seriously hampers economic activities and the current structure of the economy of Cameroon, based on finite and exhaustible resources, is unsustainable (Ministry of Energy and Water resources, 2011). Diesel and other fossil fuels are non-renewable resources, and can potentially become scarce in the long-run. Moreover, they produce greenhouse gases, which, in turn, accelerate climate change phenomenon for the whole globe. Thus, for future years, it would be a proper time for the government to start exploring a variety of alternative and clean fuel options that suit for the nation in the long-run. It should be noted that the switch of energy resources would require large amount of resources, investment, manpower, and time. Energy planning in Cameroon with considerations of alternative fuels is required to ensure energy security and sustain the social and economic growth in the country for future years.