highly significantp < 0.001
However, three variables were found to have highly significant correlations (p < 0.001) with TCL at every scale and region assessed—FDI (positively correlated at each scale/region), percent of rural population (negatively correlated at each scale/region with a slightly weaker correlation in Africa [p < 0.01]), and GDP per capita (positively correlated across scales/regions except for Africa, which was negatively correlated at the p < 0.01 level) (Supplementary Figs.