Convergence in ecological footprint across the member states of ECOWAS: evidence from a novel panel unit root test

In this paper, we investigate the convergence in ecological footprint per capita across the ECOWAS (Economic Community of West African States) countries from 1968 to 2017. For this aim, we apply a panel Fourier threshold unit root test recently proposed by Yilanci et al. (2021). This methodology considers both multiple smooth structural changes and nonlinearity, which allows us to get more reliable results. The results of the study support the evidence of nonlinearity for the series, so we test the null of divergence in a nonlinear framework. Since test statistics are statistically significant, we conclude that there is global convergence for the sample. Besides, we find that the type of convergence is absolute, which supports the view that the ecological footprint of the ECOWAS countries will equalize in the long run, and the emission allocation policies should be given priority by policymakers.