Affiliation: | 1. Nicholas School of the Environment, Duke University, Box 90328, Durham, NC 27708, United States;2. Curriculum for the Environment and Ecology, University of North Carolina at Chapel Hill, CB# 3275, Chapel Hill, NC 27599-3135, United States;3. Kenan Institute for Ethics, Duke University, Box 90432, Durham, NC 27708, United States;4. Carolina Population Center, University of North Carolina at Chapel Hill, CB# 8120, Chapel Hill, NC 27516-2524, United States |