Recent optimism about sustainability has centred on the opportunities for improvements in environment efficiency through the international diffusion of environmentally beneficial innovations. This paper investigates two claims about the conditions under which countries are most likely to realise...

This article provides a statistical analysis of the determinants of Arab aid allocation using Heckman's two-step estimator. It is found that poorer, Arab, Islamic and Sub-Saharan African countries are more likely to receive some positive amount of Arab aid (gate-keeping stage). The same is true...