Susan Cotts Watkins died peacefully in her sleep at her home in Santa Monica on August 26, 2024, at the age 85. Susan was an eminent demographer and sociologist and a leader in research on social networks, gender, fertility, and AIDS in Africa. She spent her professional life trying to unravel the mysteries of dramatic, widespread, and consequential changes in sex and death: first the historical declines in fertility in Europe and the U.S., then the global spread of fertility control, and finally the role of informal social networks in responses to the AIDS epidemic in Africa. She served as President of the Social Science History Association in 1993-4, Vice President ...