appointments in departments, and students generally get Ph.D.s in a single discipline. In making judgments about whom to hire, promote, and grant tenure, there may not be an appreciation for the additional time it takes to do top-quality interdisciplinary research, or for the fact that multiple players are involved and, as a result, most publications are multiauthored. At least in social science departments, coauthors of multiauthored works may not be given credit commensurate with their contributions when it comes to promotion and tenure decisions. Publication may also pose problems. The editors of the most prestigious journals in individual disciplines may not be interested in, or competent to review, interdisciplinary research. These difficulties pose particular problems for scientists in their early careers who work in interdisciplinary teams. Efforts must be made to overcome these institutional and cultural barriers.
Finally, these challenges of interdisciplinarity raise questions about how best to train students to contribute to population–environment research. Although there are hundreds of undergraduate programs across the country with names like environmental studies and environmental science, they vary widely in terms of the disciplines included and in rigor. Graduate programs vary less in rigor, but the opportunities for interdisciplinary work by graduate students vary considerably. Systematic in-depth and rigorous training in the full range of social and environmental sciences relevant to population–land use–environment research is comparatively rare at the graduate level, compared with training in multiple disciplines in either the social or natural sciences.