1 Humboldt-Universität zu Berlin, Geography Department, Unter den Linden 6, 10099 Berlin, Germany; University of Zürich, Epidemiology, Biostatistics, and Prevention Institut, Hirchengraben 84, 8001 Zürich, Switzerland. Electronic address: oliver.gruebner@gmail.com.
2 Loughborough University, School of Business and Economics, Centre for Information Management (CIM), Loughborough, Leicestershire, LE11 3TU, UK. Electronic address: M.D.Sykora@lboro.ac.uk.
3 Montclair State University, Department of Psychology, 1 Normal Avenue, Montclair, NJ, USA. Electronic address: lowes@mail.montclair.edu.
4 Wilfrid Laurier University, Department of Health Sciences, 75 University Avenue West, N2L 3C5 Waterloo, Ontario, Canada. Electronic address: ketan.shankardass@gmail.com.
5 Boston University, School of Public Health, 715 Albany Street, Talbot 301, Boston, MA 02118, USA. Electronic address: sgalea@bu.edu.
6 Harvard T.H. Chan School of Public Health, Department of Social and Behavioral Sciences, 677 Huntington Avenue, Boston, MA 02115, USA. Electronic address: svsubram@hsph.harvard.edu.