Demographics of Ageing: Global and Zambian Trends

The demography of ageing represents one of the most significant demographic transformations in human history (UNFPA, 2025). Understanding these trends is essential for anticipating the social, economic, and healthcare needs of ageing populations.

Global Demographic Trends

As of 2025, the global population stands at approximately 8.232 billion people (UNFPA, 2025). The proportion of older persons has increased dramatically: in 1975, older persons (aged 65+) constituted 5.5% of the global population; by 2025, this figure had risen to 10% (WHO, 2025). Meanwhile, the proportion of children has decreased from 37% in 1975 to 25% (UNFPA, 2025). The working-age population (15-64 years) now comprises 65% of the global population (UNFPA, 2025).

Global Population by Age Group, 1975-2025. Source: UNFPA (2025)

The population aged 60 and over reached 1.2 billion in 2025 and is projected to almost double by 2050 (WHO, 2020). The UN has proclaimed 2021-2030 as the "Decade of Healthy Ageing," recognising the urgent need for global collaboration to improve the lives of older people (WHO, 2020). Between 2019 and 2030, the number of persons aged 60 years or over is projected to grow by 38%, from 1 billion to 1.4 billion (UNFPA, 2025).

Table 1.2: Global Demographic Indicators, 2025

Indicator	Value
Total Population	8.232 billion
Population aged 0-14	24%
Population aged 15-64	65%
Population aged 65+	10%
Life Expectancy (Male)	71 years
Life Expectancy (Female)	76 years
Total Fertility Rate	2.2 children per woman

Source: UNFPA World Population Dashboard, 2025

The Support Ratio Challenge

The support ratio (or dependency ratio) measures the number of working-age individuals available to support each elderly person. A lower ratio indicates a greater burden on the working-age population and the overall economy. As populations age, this ratio declines, creating significant economic and social challenges.

Zambian Demographic Trends

Zambia presents a markedly different demographic profile compared to global averages. As of 2025, Zambia's total population is approximately 21.9 million (UNFPA, 2025). The country has a very young population structure (World Economics, 2025):

·        Population aged 0-14: 41%

·        Population aged 15-64: 57%

·        Population aged 65 and older: 2%

Figure 1.2: Zambia's Population Pyramid, 2025. Source: UNFPA (2025)

Life expectancy in Zambia is lower than the global average: 64 years for males and 69 years for females (UNFPA, 2025). The total fertility rate remains high at 4 children per woman (World Economics, 2025).

However, Zambia is experiencing a gradual ageing of its population. The average age of the population in 2025 was 17.94 years, which has been growing for 16 consecutive years (World Economics, 2025). The population aged 18 years or older reached 11.4 million in mid-2025, representing a 3.8% increase from 2024 (UNFPA, 2025).

Table 1.3: Zambia's Demographic Indicators, 2025

Indicator	Value
Total Population	21.9 million
Population aged 0-14	41%
Population aged 15-64	57%
Population aged 65+	2%
Life Expectancy (Male)	64 years
Life Expectancy (Female)	69 years
Total Fertility Rate	4.0 children per woman
Support Ratio (workers per elderly dependent)	28.5 workers

Source: UNFPA World Population Dashboard, 2025; World Economics, 2025

Implications for Zambia

Despite currently having a relatively small proportion of older adults (2% aged 65+), Zambia faces several important considerations (Cohen, 2020):

1.     The support ratio is projected to decline significantly: In 2025, there were approximately 28.5 workers per elderly dependent; by 2050, this figure is estimated to drop to 7.1 workers (UNFPA, 2025). This represents a dramatic shift that will require policy preparation (United Nations, 2022).

2.     Rapid population growth and urbanisation: With a population annual doubling time of 25 years (World Economics, 2025), Zambia's population structure is changing rapidly, with implications for intergenerational support systems (Harper, 2014).

3.     Traditional family care systems: In Zambian and broader African contexts, older adults have traditionally been cared for within extended family networks . Urbanisation and changing family structures may challenge these traditional support systems (Banda, 2025).

4.     The "double burden": Zambia faces the challenge of addressing both communicable diseases (affecting younger populations) and the emerging burden of non-communicable diseases associated with ageing (WHO, 2025).

Self-Assessment Exercise 1.2

Instructions: Reflect on the following questions and write brief responses. Check your answers against the tips provided.

1.     Question: Compare the demographic profile of Zambia with the global average. What are the three most significant differences, and what do they suggest about Zambia's future ageing trajectory?

2.     Question: What is the support ratio, and why is its projected decline from 28.5 to 7.1 workers per elderly dependent in Zambia significant? What policy implications does this have?

3.     Question: How might urbanisation and changing family structures in Zambia affect the traditional care of older adults?

Answer Tips:

·        For Question 1: Key differences include: (1) Zambia has a much higher proportion of children (41% vs 24% globally) and much lower proportion of older adults (2% vs 10%); (2) Zambia has higher fertility (4.0 vs 2.2) and lower life expectancy (Harper, 2014); (3) Zambia is in an earlier stage of demographic transition but will experience significant ageing in coming decades, requiring preparation now (Cohen, 2020).

·        For Question 2: The support ratio measures how many workers support each older person (Kinsella & He, 2009). A decline from 28.5 to 7.1 means far fewer workers will support each older adult, increasing economic pressure on social security, healthcare, and family support systems (United Nations, 2022). Policy implications include the need for pension reform, healthcare system strengthening, and promoting healthy ageing to reduce dependency (WHO, 2020).

For Question 3: Urbanisation often reduces the proximity of extended family members who traditionally provided care (Harper, 2014). Changing family structures (smaller families, women's workforce participation) may reduce available caregivers, potentially increasing demand for formal care services and requiring new policy approaches to elder care