Dirk Jan van de Kaa passed away in The Hague, The Netherlands on 22 May 2026 at the age of 93 years. He was survived by his wife Jacomien, his daughter Marjan, and his son Jan Hein.
Dirk van de Kaa was the founding father of contemporary Dutch demography and a pilar of the scientific study of population in the Netherlands. As an eminent scientist and administrator of national and international acclaim, his impact crossed geographic and disciplinary borders, and his academic achievements were complemented by outstanding services to the national and international scientific communities.
Founding director of the Netherlands Interdisciplinary Demographic Institute NIDI (1971-1987), first President (1983-1987) and Honorary President (since 1987) of the European Association for Population Studies EAPS, professor of Demography at the University of Amsterdam (1977-1998), Project-Director of the World Fertility Survey (1981-1982), Director of the International Statistical Research Centre (1982-1984), Vice-President of the Royal Netherlands Academy of Arts and Sciences (1984-1987), Rector/Director of the Netherlands Institute for Advanced Study in the Humanities and Social Sciences (1987-1995) and Vice-President of the Netherlands Organization for Scientific Research (1988-1998) are part of his lasting legacy.
As scientific secretary of the Royal Netherlands Commission on Population (1972-1977) Dirk van de Kaa forged bridges between the scientific and policy communities and laid the foundation for the development of population-related policies, as did his work as chair of the Netherlands Interministerial Committee on Population Questions (1987-1994) and his work at the Population Commission of the United Nations (1971-1987).
His services to the scientific community further included memberships and leading roles in various learned societies in the Netherlands and abroad including several Academies of Science. Dirk van de Kaa was the proud holder of multiple scientific awards including the 2001 Laureate of the International Union for the Scientific Study of Population IUSSP, and the 2022 EAPS Award for Population Studies.
After his studies in the social sciences and geography at Utrecht University where he graduated in 1959, Dirk van de Kaa went to Australia to pursue his studies in demography. His work on a demographic research project in Western New Guinea and later as a Research Fellow at the Demography Department of the Australian National University in Canberra, culminated in taking his PhD in Demography at the Australian National University with a thesis on The Demography of Papua-New Guinea’s Indigenous Population (1971). While he liked to refer to Australia as his second homeland, he was invited to return to the Netherlands in 1971 to become the founding Director of the Netherlands Interuniversity Demographic Institute NIDI, an institute that he led until 1987.
In addition to his policy-oriented scientific work, his extensive bibliography ranges widely. But for many colleagues his groundbreaking work on the Theory of the Second Demographic Transition, jointly formulated with his Belgian colleague Ron Lesthaeghe, as a framework to understand modern population dynamics, will especially be remembered.
For many, it has been a great privilege to collaborate with Dirk van de Kaa, who will not only be remembered as a highly reputed and learned scientist, but also as a person of great integrity and wisdom. Dirk will be dearly missed and remembered with kindness by many.
Nico van Nimwegen
Helga de Valk
30 May 2026
