academic researchers. Little systematic knowledge exists, however, about which barriers are most significant for particular lines of research or about which interventions are most effective in reducing impediments to the progress of research or the training of future researchers.

Organizations that support population–environment research should support a systematic assessment of which approaches seem to result in the best and most rigorously trained young scholars in this field and the most productive research collaborations. This assessment should be based on systematic analysis of experience from population-environment research and related interdisciplinary fields. It should address such questions as these: Does strong interdisciplinary training at the undergraduate or graduate levels make young scholars more effective at interdisciplinary collaboration? Are experienced graduate or postdoctoral mentors necessary to motivate and train interdisciplinary collaborators? Are graduate students and junior faculty who participate in interdisciplinary projects hindered in their careers, or is the perception that interdisciplinary participation is risky partially or entirely mythical? What differentiates effective from ineffective leaders of interdisciplinary teams? How do effective interdisciplinary teams recruit and reward participants? Do certain types of administrative structures, such as interdisciplinary research institutes, foster successful interdisciplinary research? What styles of communication and administration favor successful operation of dispersed multiinstitution and international collaborations?