An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
1 Christopher Dye is a professor of epidemiology in the Department of Zoology at the University of Oxford, Oxford, UK. christopher.dye@zoo.ox.ac.uk.
2 Melinda C. Mills is director of the Leverhulme Centre for Demographic Science and a professor of sociology at the University of Oxford, Oxford, UK. melinda.mills@nuffield.ox.ac.uk.
1 Christopher Dye is a professor of epidemiology in the Department of Zoology at the University of Oxford, Oxford, UK. christopher.dye@zoo.ox.ac.uk.
2 Melinda C. Mills is director of the Leverhulme Centre for Demographic Science and a professor of sociology at the University of Oxford, Oxford, UK. melinda.mills@nuffield.ox.ac.uk.