About the Authors

Warren C. Sanderson

Contributed equally to this work with: Warren C. Sanderson, Sergei Scherbov

warren.sanderson@stonybrook.edu

Affiliations Department of Economics, Stony Brook University, Stony Brook, New York, United States of America, World Population Program, International Institute for Applied Systems Analysis, Laxenburg, Austria, Wittgenstein Centre for Demography and Global Human Capital (IIASA, VID/ÖAW, WU), IIASA, Laxenburg, Austria

Sergei Scherbov

Contributed equally to this work with: Warren C. Sanderson, Sergei Scherbov

Affiliations World Population Program, International Institute for Applied Systems Analysis, Laxenburg, Austria, Wittgenstein Centre for Demography and Global Human Capital (IIASA, VID/ÖAW, WU), IIASA, Laxenburg, Austria

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: WCS SS. Performed the experiments: WCS SS. Analyzed the data: WCS SS. Contributed reagents/materials/analysis tools: WCS SS. Wrote the paper: WCS SS.