Pope Francis has named Jeffrey Sachs, the controversial Columbia University economist and proponent of population control, to be a member of the Pontifical Academy for Social Sciences.

Sachs has been a leading figure in the UN’s sustainable-development drive. A frequent critic of US foreign policy, he has been criticized for his ties to China and his unwillingness to condemn Chinese human-rights abuses.

Sachs has been a regular participant in Vatican conferences on development and other economic topics during the current pontificate.