Is export-led growth hypothesis still valid for sub-Saharan African countries? New evidence from panel data analysis

Purpose - This study examines the causal relationship between exports and economic growth in sub-Saharan African (SSA) countries during the period 1980 to 2017. The study also examines whether the causality between these two macroeconomic variables depends on the countries' stage of development as proxied by their per capita income. Design/methodology/approach - The study uses a panel cointegration test and panel Granger-causality model to examine the link between exports and growth. The study also incorporates external debt as an intermittent variable in a bivariate setting between exports and economic growth, thereby creating a dynamic multivariate panel Granger-causality model. Findings - Although the study found the existence of a long-run relationship between exports and economic growth, the study failed to find any export-led growth response in both low-income and middle-income countries. Instead, the study found evidence of a bidirectional causality and a neutrality response in middle-income and low-income countries, respectively. The study, therefore, concludes that the benefits of an export-led growth hypothesis may have been oversold, and that the strategy may not be desirable to some low-income developing countries. Practical implications - These findings have important policy implications as they indicate that the causality between exports and economic growth in SSA countries varies with the countries' stage of development. Consistent with the contemporary literature, the study cautions low-income SSA countries against over-relying on an export-led growth strategy to achieve a sustained growth path as no causality between exports and economic growth has been found to exist in those countries. Instead, such countries should consider pursuing new growth strategies by building the domestic demand side of their economies alongside their export promotion strategies in order to expand the real sector of their economies. For middle-income countries, the study recommends that both export promotion strategies and pro-growth policies should be intensified as economic growth and exports have been found to reinforce each other in those countries. Originality/value - Unlike the previous studies, the current study disaggregated the full sample of SSA countries into two subsets – one comprising of low-income countries and the other consisting of middle-income countries. In addition, the study uses a multivariate Granger-causality model in order to address the emission-of-variable bias. To our knowledge, this may be the first study of its kind in recent years to examine in detail the causal relationship between exports and economic growth in SSA countries using an ECM-based multivariate panel Granger-causality model. 研究目的 - 本研究旨在探討在1980年至2017年期間撒哈拉以南非洲國家的出口、與其經濟增長之間的因果關係，亦探討這兩個宏觀經濟變量之間的因果關係、會否取決於有關國家所處以人均收入來衡量的發展階段。 研究結果 - 本研究雖然發現出口與經濟增長存有一個長期性關係，唯未能於低收入國家或中等收入國家、找到任何出口帶動的增長反應。研究反而找到證據，證實中等收入國家為一雙向性因果關係反應，而低收入國家則為一中立性反應。因此，研究的結論是：出口必能帶動經濟增長這假設被過度吹噓，而且，對部份低收入發展中國家而言，實施以出口帶動經濟增長的策略或許是沒有用的。 實際意義 - 本研究的結果在政策方面有其重要意義。這是因為研究結果顯示、於撒哈拉以南非洲國家、出口與經濟增長之間的因果關係，會因有關國家所處的發展階段而有所變更。與當代文獻一樣，本研究提醒低收入的撒哈拉以南非洲國家，不要過度依賴以出口帶動增長的策略來謀求踏上持續增長之路，這是因為在這些國家，出口與經濟增長之間的因果關係仍未確立。他們反而應考慮推行新增長經濟策略，方法是在實施推動出口的策略的同時，也要建立其經濟的國內需求面，以擴大其經濟實業部門。就中等收入國家而言，本研究建議他們應增強推動出口的策略及強化促進增長的政策，這是因為在這些國家裏，經濟增長及出口已被證實會互為增強。 原創性／價值 - 有別於過去的研究，本研究把撒哈拉以南非洲國家的整體樣本分解為兩個子集：一個包括低收入國家，另一個則包括中等收入國家。而且、研究使用了多變量面板格蘭傑因果關係模型、以處理遺漏變數偏差的問題。據我們了解，這大概是近年首個同類研究、以基於歐洲共同市場多變量面板格蘭傑因果關係模型、來詳細探討於撒哈拉以南非洲國家、出口與經濟增長之間的因果關係。