Environmental Change and Human Migration in the Developing World
This line of research focuses on the consequences of environmental change for human migration, an issue which has gained considerable attention in the context of global climate change and recent large-scale natural disasters. Using data from a variety of settings, my research with collaborators confirms that environmental factors have important influences on migration, but the results are not consistent with Neo-Malthusian predictions that environmental degradation will universally displace permanent migrants over long distances. Instead, the majority of climate migrants are likely to move temporarily and/or over short distances, and some potential migrants are likely to be trapped in place.
Funding: NIH (R00-HD061752, R03-HD083528, R03-HD098357)
Trainees: Maia Call, Doug Hopping
Publications: Gray 2011; Gray & Mueller 2012a, Gray & Mueller 2012b, Fussell et al. 2014; Gray et al. 2014; Mueller et al. 2014; Jennings & Gray 2015; Gray & Wise 2016; Thiede et al. 2016; Thiede & Gray 2017; Call et al. 2017; Mueller et al. 2020a; Mueller et al. 2020b; Gray et al. 2020; Williams & Gray 2020; Call & Gray 2020; Thiede et al. 2022
Work in progress: Call & Gray 2019
Media: Climate Outreach; Development Impact; IFPRI 1; IFPRI 2; The Nation (Pakistan); Nature Climate Change; New Security Beat; Population Reference Bureau 1; Population Reference Bureau 2; Scientific American; SciLogs; Simple Climate; Slate; Smithsonian Magazine

Climate, Health and Population Well-being
This line of research investigates the consequences of climate variability for multidimensional population well-being across the developing world. By linking large-sample and longitudinal population data sources to spatial data on climate, this work provides new insights into the impacts of future climate change on human development.
Funding: NIH (R03-HD083528, R03-HD101859, R03-HD104843)
Trainees: Heather Randell, Erika Munshi, Sandeep Kandikuppa, Katie McMahon, Sara Ghebremicael, Georgina Gemayel
Publications: Randell & Gray 2016; Jennings & Gray 2017; Call et al 2019; Randell & Gray 2019; Sellers & Gray 2019; Randell et al. 2020; Thiede & Gray 2020; Nicholas et al. 2021; McMahon & Gray 2021
Work in progress: Gray et al 2019; Randell et al. 2022; Jackson et al. 2022; Ghebremicael et al. 2022
Media: Anthropocene Magazine; Carolina Planning Journal; New Security Beat; New Security Beat 2; Time Magazine; UNC


Changing Indigenous Livelihoods and Land Use in the Ecuadorian Amazon
Building on a baseline data collection conducted in 2001, we constructed an 11-year longitudinal dataset on the demographic and environmental behaviors of 500 indigenous households from five ethnicities in the Northern Ecuadorian Amazon. Analyses of these data investigated the patterns and drivers of indigenous fertility, migration, wild product harvesting, land use and off-farm employment.
Funding: NIH (R00-HD061752)
Trainees: Matt Bozigar, Jason Davis, Sam Sellers, Victoria Salinas
Publications: Gray et al. 2008, Lu et al. 2010, Davis et al. 2015, Gray et al. 2015a, Gray et al. 2015b, Bozigar et al. 2016; Davis et al. 2017; Salinas Castro et al 2020; Sellers & Bilsborrow 2020; Gray & Bilsborrow 2020; Thiede & Gray 2020
Media: UNC Geography

Soil Degradation and Rural Livelihoods in Uganda
Building on a baseline data collection conducted in 2003, we constructed a 10-year longitudinal dataset on soil degradation, poverty and rural livelihoods in Uganda covering 700 households and 2000 agricultural plots. Analyses of these data are investigated the patterns, drivers and consequences of soil degradation for agricultural households.
Funding: NSF (BCS-1226817)
Trainees: Maia Call, Leah Bevis, Josh Minai
Publications: Minai 2015; Bevis et al. 2017; Call et al. 2019; Bevis & Barrett 2019; Call & Gray 2020; Bevis & Hestrin 2020a; Bevis & Hestrin 2020b
Media: Development Impact; Economics That Really Matters 1; Economics That Really Matters 2

Out-Migration and Rural Livelihoods in the Southern Ecuadorian Andes
Using an innovative sampling approach, this project collected retrospective data on migration from 1200 rural households who were linked to spatial data on climate, topography and vegetation. Analyses of these data examined the contribution of environmental factors to internal and international migration, as well as the consequences of migration for rural land use.
Funding: NSF (BCS-0525469), NIH (R21-HD052092)
Publications: Gray 2009a, Gray 2009b, Gray 2010, Gray & Bilsborrow 2013; Gray & Bilsborrow 2014