In a companion paper [Dechezlepretre, A., Glachant, M., Meniere, Y., 2008. The Clean Development Mechanism and the international diffusion of technologies: An empirical study, Energy Policy 36, 1273-1283], we gave a general description of technology transfers by Clean Development Mechanism (CDM) projects and we analyzed their drivers. In this paper, we use the same data and similar econometric models to explain inter-country differences. We focus on 4 countries gathering about 75% of the CDM projects: Brazil, China, India and Mexico. Sixty eight percent of Mexican projects include an international transfer of technology. The rates are, respectively, 12%, 40% and 59% for India Brazil and, China. Our results show that transfers to Mexico and Brazil are mainly related to the strong involvement of foreign partners and good technological capabilities. Besides a relative advantage with respect to these factors, the higher rate of international transfers in Mexico seems to be due to a sector-composition effect. The involvement of foreign partners is less frequent in India and China, where investment opportunities generated by fist growing economies seem to play a more important role in facilitating international technology transfers through the CDM. International transfers are also related to strong technology capabilities in China. in contrast, the lower rate of international transfer (12%) in India may be due to a better capability to diffuse domestic technologies. (C) 2008 Elsevier Ltd. All rights reserved.