Rapid development of technology and great achievements in health in recent decades have resulted in fast changes of demographic issues. Discussions of high fertility rates have been replaced by discussions relating to low fertility and its impacts in not only developed countries but also some developing countries where fertility has reached the replacement level. The concerns to mortality are gradually replaced by concerns to aging, provision of social security to the elderly, and healthy life. Migration, both internal and international ones, have increased in many countries as a consequence of globalization and economic development.

Vietnam is an even more interesting case for population and urbanization studies as the country has gone through socioeconomic reforms and rapid changes over the past three decades. The fertility was already at replacement level, mortality was relatively low given the country's level of economic development, migration and urbanization increased quickly in the past decade.

Major areas of interest of PHAD in the population and urbanization studies include:

• Low fertility in developing countries;
• Population aging and social security for the elderly;
• Disability and health expectancy;
• Internal migration to urban areas and its impacts;
• Labor and marriage emigration;
• Urbanization and social problems, especially health problems, in urban areas.