Supercentenarians and the theory of heterogeneity • James W. Vaupel, Max Planck Institute for Demographic Research ; Jutta Gampe, Max Planck Institute for Demographic Research

Constant global population with demographic heterogeneity • Joel E. Cohen, Rockefeller University and Columbia University

Toward a demographic theory of societal change with predictive power • Wolfgang Lutz, International Institute for Applied Systems Analysis (IIASA)

The impact of freedom on fertility transition: revisiting the theoretical framework • Martha M Campbell, University of California, Berkeley ; Ndola Prata, University of California, Berkeley ; Malcolm Potts, University of California, Berkeley