A spatial econometric analysis of the environment Kuznets curve and pollution haven hypothesis in Sub-Saharan Africa

Abstract

The aim of this study is to test the environment Kuznets curve (EKC) and pollution haven (PH) hypotheses in Sub-Saharan Africa (SSA). An important methodological point that has been over-looked by many studies is that environmental quality is not only correlated in time but also in space. For this purpose, the study applies spatial panel econometric analysis using a balanced panel of 35 SSA nations from 2002 to 2015 to examine the EKC and PH hypotheses. Both spatial interdependence and individual heterogeneity are accounted for through the application of the spatial Durbin model (SDM) so as to avoid potential bias and inefficiencies in parameter estimates. As proxies for environmental quality, panel data aggregates on carbon dioxide (CO2) emissions and the depletion of natural resources are utilised. The findings offer proof for the EKC theory about the depletion of natural resources in SSA. The EKC theory, however, does not apply to CO2 emissions. Moreover, the study finds that the positive scale effect of trade outweighs the negative technique effect of trade, which indicates that trade liberalisation has a negative effect on both environmental quality indices. This discovery supports the PH theory. The study also demonstrates positive spatial spill-over for natural resource depletion between neighbouring countries and negative spatial spill-over for carbon dioxide emission between close countries.