“…Anastacio (2017) investigated the EKC in three NAFTA countries, and other studies investigated the EKC hypothesis in the single-country case of the NAFTA region (e.g., Burnett, Bergstrom, & Wetzstein, 2013;Dogan & Turkekul, 2016;Lantz & Feng, 2006;Lipford & Yandle, 2011;Olale et al, 2018). Other than EKC, some studies also investigated the role of FDI, trade, and FMD in the pollution emissions in the single-country analysis of the NAFTA region (Dogan & Turkekul, 2016;Gale, 1995;Shahbaz et al, 2019;Waldkirch & Gopinath, 2008). But, the role of the mentioned variables in the pollution emissions of the whole North American region is missing in the literature, and spatial dependency of pollution emissions of this region also needs attention.…”