Institute of Applied Systems Analysis (IASA), Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.
Department of Mathematics and Statistics, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana.
Environ Sci Pollut Res Int. 2020 Nov;27(31):38674-38694. doi: 10.1007/s11356-020-09880-0. Epub 2020 Jul 6.
The main aim of this current study is to empirically scrutinize the determinants of energy consumption for 24 African countries sub-grouped into three panels based on income levels: low-, lower-middle-, and upper-middle-income countries, from 1990 to 2015. Due to the presence of heterogeneity and cross-sectional reliance among country groups, recently developed econometric approaches, which include cross-sectional Im, Pesaran, and Shin together with cross-sectional Augmented Dickey-Fuller stationarity tests, Pedroni and Westerlund-Edgerton cointegration assessment, dynamic common correlated effect estimation approach and Dumitrescu-Hurlin Granger causality test are employed. Empirically, our findings depict analyzed variables are stationary and characterized by long-term stability affiliations for all panels. Economic growth, urbanization, population growth, and oil price with labor and capital stock as intermittent variables had palpable significant positive sway on energy consumption for all panels though their respective weight of contribution differed from one country group to another. The granger test of causation unveiled that (i) among all panels, urbanization and energy consumption are connected bidirectionally, whereas population growth causes energy consumption; (ii) a one-way causal link from economic growth to energy use is evidenced in low-income African countries, whereas a two-sided connection is confirmed in both lower-middle- and upper-middle-income economies; (iii) a bilateral causal association in low-income African nations is observed amid oil price and energy use, while a uni-lateral relationship extends from oil price to energy consumption in both lower-middle- and upper-middle-income nations in Africa. Such new methodologies and findings reveal that the long-term estimated effects as well as causal affiliations amid variables are skewed by different income levels of African countries in an attempt to conserve energy. Policy recommendations are further propose.
本研究的主要目的是实证考察 24 个非洲国家的能源消费决定因素，这些国家根据收入水平分为三个小组：低收入、中下收入和中上收入国家，时间跨度为 1990 年至 2015 年。由于国家组别之间存在异质性和横截面依赖性，因此采用了最近开发的计量经济学方法，包括横截面 Im、Pesaran 和 Shin 以及横截面增广迪基-富勒（ADF）单位根检验、Pedroni 和 Westerlund-Edgerton 协整评估、动态共同相关效应估计方法和 Dumitrescu-Hurlin 格兰杰因果检验。实证结果表明，分析变量在所有面板中均为平稳变量，具有长期稳定关系。经济增长、城市化、人口增长和石油价格以及劳动力和资本存量作为间断变量，对所有面板的能源消费都有明显的正向影响，尽管它们各自的贡献权重因国家组别而异。因果关系的格兰杰检验表明：（i）在所有面板中，城市化和能源消费之间存在双向关系，而人口增长则导致能源消费；（ii）在低收入非洲国家，经济增长与能源使用之间存在单向因果关系，而在中下收入和中上收入经济体中，则证实了双向关系；（iii）在低收入非洲国家中，石油价格和能源使用之间存在双边因果关系，而在中下收入和中上收入非洲国家中，石油价格与能源消费之间则存在单向关系。这些新的方法和发现表明，长期估计的效应以及变量之间的因果关系因非洲国家的不同收入水平而存在偏差，这是为了节约能源。进一步提出了政策建议。
