This book delivers a compelling exploration of Southeast Asia’s fertility transition, highlighting both cross‑country contrasts and within‑country diversity. It examines ultra‑low fertility nations such as Singapore and Thailand alongside higher‑fertility countries like Timor‑Leste, while uncovering socio‑economic and regional variations within individual nations. Drawing on national surveys and global datasets from the United Nations and World Bank, it provides a comprehensive, data‑driven analysis of how education, employment, urbanization, family wealth, contraceptive use, and delayed marriage influence fertility behaviors. Beyond demographic patterns, the book connects fertility trends to economic growth, policy innovation, and urgent challenges such as aging populations, shrinking workforces, and economic sustainability. Offering practical frameworks for population policies informed by successful practices within and beyond the region, it aligns with the International Conference on Population and Development priorities and the Sustainable Development Goals. A vital resource, it highlights the consequences of declining fertility and the demographic diversity shaping Southeast Asia today.

Siow Li Lai (PhD) is Associate Professor, Coordinator of Population Studies Unit, and Data Manager (Liaison Officer with the Department of Statistics) at Universiti Malaya.
Nai Peng Tey (PhD) is a demographer at Universiti Malaya, board member of National Population and Family Development Board, and Adjunct Professor at Mahidol University.