This paper addresses policy effects of international mobility in developing countries. It proposes a multilevel approach to study research training policies, specifically focusing on international mobility schemes as capacity-building instruments, where effects need to be identified at both individual and organizational levels. The paper asserts that current categorizations of country efforts to build a solid scientific base should consider transference of effects in domestic research contexts. Using a survey and interview-based study of a mobility policy in Mexico, and nanotechnology-related disciplines and sectors, this paper's findings suggest that mobility policies are crucial in creating high-quality individual research skills, but that their impact on building domestic research capacity may be modest. This paper contributes to the evaluation literature on national research training programs and their influence on research capacity in two ways. First, it mobilizes a multilevel analytical approach to examine the effects of policies on individuals and organizations, offering a broader conceptualization of impact. Second, by introducing these individual and organizational effects, the paper provides insights into how effects are enacted and transferred.