Refers to the demographic process by which the proportion of older individuals within a population increases over time. This phenomenon occurs primarily because of two converging trends: longer life expectancies and declining birth rates. As a result, the median age of the population rises, and older adults make up a growing share of society. The term is widely recognized and used by major international and national organizations:

• The United Nations (UN) defines population aging as the increasing share of older persons in the total population, emphasizing its global nature and connection to fertility and mortality trends.
• The World Health Organization (WHO) describes it as a global phenomenon that carries significant implications for public health, social policy, and economic systems.
• The Organization for Economic Cooperation and Development (OECD) and U.S. Census Bureau use the term in analyzing demographic shifts and their effects on labor markets, retirement systems, and healthcare demands.

In the learning and work context, population aging is a key factor driving what many analysts refer to as workforce aging—the steady increase in the average age of employees in the labor force. This trend affects talent pipelines, succession planning, workplace design, and employer strategies for retaining experienced workers. While most employers recognize the changing age composition of the workforce, most have not taken proactive steps to engage and leverage the experience, institutional knowledge, and mentoring potential of employees aged 50 and older.

Related Terms

• Aging population – Often used interchangeably with population aging, particularly in media and general public discussions.
• Ageing society (British spelling: ageing) – Common in international policy and research contexts, especially in Europe and Asia, to describe societal-level impacts of aging populations.
• Demographic aging – Emphasizes the structural demographic change rather than individual aging; used frequently in academic and policy research.
• Silver economy – Describes the economic opportunities, markets, and industries emerging from the spending power and participation of older adults.
• Workforce aging – Refers specifically to the increasing average age of the labor force; used in human resources, labor economics, and workforce development literature.