2.1.2 Household size and composition
Helpful prior knowledge and learning objectives
Helpful prior learning:
Section 1.1.1 The economy and you, which explains what an economy is and how it is relevant to students’ lives
Section 1.1.2 The embedded economy, which explains the relationship between the economy and society and Earth’s systems.
Section 1.3.4 Doughnut Economics model, which explains a model for considering meeting human needs within planetary boundaries
Section 1.3.5 Provisioning systems, which explains how the physical and social parts of economic systems mediate between biophysical inputs and social outcomes.
Section 2.1.1 The household as a system, which describes households, the basic relationships of household members, and the connection between the household and the rest of the economy.
Section S.1 Systems thinking, which explains what a system is and why systems thinking is useful. (coming soon)
Learning objectives:
outline global differences in household size and composition and the role of demographic transition in those differences
discuss the impact of household size and composition on the ability of the economy to meet human needs within planetary boundaries
The living arrangements of the Patil family from Mumbai, India have changed dramatically over recent generations. In the 1970s, the Patil household was bustling, filled with four generations under one roof—great-grandparents, grandparents, parents, and children. These ‘joint families’ were typical in India at the time, where kinship bonds and economic conditions kept extended families together in large, shared living spaces even in large cities. By the 2020s, the family's living situation was very different. The younger Patil, Raj, now lives in a modern apartment building with just his wife and their daughter.
This shift from a large, multi-generational household to a smaller, nuclear family household reflects broader trends across India and globally. Influenced by urbanisation, rising incomes, changing values, education and employment trends, nuclear families are more common now. However, there are significant differences between countries and regions in the trends in household composition. And at an individual household level, household composition can be very fluid depending on the needs of household members.
This section discusses global differences and changes over time in the size and composition of households and the economic, social and ecological consequences of these changes.
Figure 1. Households have become smaller over time globally. Will this trend continue?
(Credit: The Wedding Fog CC0)
How do household size and household composition differ between countries?
Household size varies significantly among countries, as shown in Figure 2. Light green indicates countries with small households, under 3 members. Dark blue indicates countries with large households, six or more people.
These household size differences are related to household composition, or who lives in the household. Countries with higher fertility rates have more young people in households. Lower-income countries often have extended families and multiple generations living together to share resources and share the care work. For example, Senegal has low average income and a high fertility rate of 4.39 children per woman (2021) and the average household size is about 10 people.
Conversely, countries with lower fertility rates and higher incomes tend to have smaller households. There are more childless households, and higher incomes allow more people to live independently, including older generations supported by private and public pensions. For instance, Germany has high average incomes, strong social security, and a low fertility rate of 1.58 (2021). There, the average household size is under two people.
Figure 3. High incomes and social security have led to more people living alone, including older generations
(Credit: CDC Unsplash licence)
How are household size and composition changing over time?
Demographic transition refers to trends over time in human birth rates, death rates and overall population growth. These trends are connected to household size and composition. A demographic transition model helps us visualise trends over time (Figure 4):
Stage 1: birth rates and death rates are high, due to limiting factors in the environment like the availability of food, predators and other factors. Population size remains low and stable. Humans experienced these conditions for most of our history.
Stage 2: Over time, humans improved healthcare and sanitation. Section 1.2.3 explains how fossil fuels gave us more energy to develop technologies to grow more food, extract more water, and do more work. Death rates declined and life expectancy increased. Birth rates remained high and human populations grew.
Figure 4. Demographic transition over time shows falling death and birth rates, slowing population growth and ageing population structures
(Credit: Max Roser Our World in Data CC BY 4.0)
Stages 3 and 4: Over time, birth rates also declined due to improved education and family planning, increased gender equality, higher incomes and more opportunities for work. Urbanisation made housing large families more difficult and expensive. Populations grew at a slower rate, shown by a less steep population growth curve, and then stabilised.
Stage 5: In the final stage of the model, human populations age and birth rates remain low. As people age, death rates may rise, and total population declines. The United Nations predicts this will happen globally around 2080. Populations in some countries like South Korea, Japan, and some parts of Europe are already falling.
The demographic transition affects household size and composition. Historically, extended families—grandparents, parents, children, and sometimes aunts, uncles, and cousins—often lived together. During Stages 1-3, households had many young children, shown by the wide bases of population pyramids in Figure 4 (discussed in Section 1.3.7).
Over time, improved healthcare, sanitation, and gender equality led to longer lives and fewer children per family, reducing household size. Higher incomes have allowed young people to establish their own households earlier, increasing the number of households, but decreasing their size.
Current differences in household size between countries are largely due to their stage in the demographic transition. In countries with poor healthcare, sanitation, and low incomes, birth rates remain high, leading to larger households. In countries with better healthcare, sanitation, higher incomes, education, gender equality, and urbanisation, birth rates are low, life expectancy is high, and households are smaller.
Figure 5. Smaller households, including one-person households, are becoming more common
(Credit: Vlada Karpovich, Pexels license)
How does household size and composition impact our ability to meet human needs within planetary boundaries?
Household size and composition impact economies, societies, and the environment, influencing how well economies can meet human needs within planetary boundaries.
Smaller households require more housing, increasing the matter and energy used to meet needs. They also need more household machines and tools (Figure 6) compared to larger households that share resources for cooking, cleaning, and housing. This increase in smaller households leads to higher environmental impacts, such as more carbon dioxide (CO2) emissions and intensive land use, harming ecosystems and biodiversity (Section 1.2.7). This puts more pressure on planetary boundaries.
Socially, the shift from larger, extended family households to smaller households increases autonomy and freedom, especially for young adults and women who might not need to care for family members. However, smaller households can reduce social cohesion and decrease community support systems traditionally provided by extended families. This could undermine wellbeing, as strong social relationships and community support are key to happiness. Yet, this is context-dependent. Smaller households can also cultivate strong social connections outside the home.
Smaller households may also rely more on markets for caring for children, elders and those with disabilities. They may pay for care outside the home, such as eldercare facilities for parents. Or they may pay for care inside the home from a domestic worker. Smaller households are a significant factor in growing global care chains of care workers who migrate to different countries to do care work. This will be explored further in Section 2.3.3.
Understanding the ecological and social impacts of household changes is crucial for economic policies on housing, welfare, and sustainability. Recognising the link between household systems and broader social and ecological outcomes helps us create better policies for regenerating social and ecological systems. Generally, smaller households make economies less efficient at meeting human needs within planetary boundaries. So one idea may be to return to larger households, perhaps through co-living arrangements. These arrangements could enhance social support and care, offering a strategy for resilient, regenerative economies.
Activity 2.1.2
Concept: Systems
Skills: Option 1 Research skills (Information literacy), Option 2 Thinking skills (critical thinking)
Time: 30 minutes
Type: Individual, pairs, or small group
Option 1 - Exploring household size and composition data for your country
Access the United Nations Interactive Data on Household Size and Composition. This provides more detailed data on household size and composition by country. Find the country where you currently live, or one that you feel connected to:
What does the data show about current household size and composition in that country?
How does that data compare to other countries (in your region, globally?)
Describe some trends over time in household size and composition. Does the data surprise you in any way?
What are the implications of these changes in household size and composition for your country’s ability to meet human needs within planetary boundaries?
Option 2 - Discussion - Single women and happiness
In 2019, Paul Dolan, a behavioural scientist at the London School of Economics, published a book called Happy Ever After. In that book, Dolan claimed that time-use data from the United States showed that single women without children were the happiest.
The data were later questioned and the claims of the book were toned down. Still, the question of the relative happiness of different groups of people based on family status, household size and composition is interesting to explore.
In small groups or as a whole class consider:
How might incomes, culture, power, laws, gender equality and other factors affect whether people are happier living alone, or in small or larger groups.
Why might there be differences between the happiness levels of women and men in these different household configurations?
What household size and composition do you think would make you happiest? Why?
Ideas for longer activities and projects are listed in Subtopic 2.5 Taking Action
Checking for understanding
Further exploration
United Nations Interactive Data on Household Size and Composition - a breakdown of more detailed data on household size and composition by country. Interesting to explore if you did not do Option 1 in the Activity box. Difficulty level: easy
Dollar Street - a website from the Gapminder organisation with photographs and videos of global households, mainly composed of kinship relationships. The website is fascinating to explore with or without a goal in mind, but you might want to notice the different household sizes and composition. Difficulty level: easy
With billions confined to their homes worldwide, which living arrangements are most common? - a Pew Research Center study on household composition worldwide. Difficulty level: medium
Global Population Growth, Box by Box - an older, but still entertaining and relevant video by the late Hans Rosling, where he explains demographic trends in family size, arguing that if we want population to stabilise, the world’s poorest must escape poverty. Difficulty level: easy
Sources
Esteve, A., Pohl, M., Becca, F. et al. A global perspective on household size and composition, 1970–2020. Genus 80, 2 (2024). https://doi.org/10.1186/s41118-024-00211-6
Roser, M. (2023) - “Demographic transition: Why is rapid population growth a temporary phenomenon?” Our World in Data. https://ourworldindata.org/demographic-transition
United Nations, Department of Economic and Social Affairs, Population Division (2019). Patterns and trends in household size and composition: Evidence from a United Nations dataset. (ST/ESA/SER.A/433). https://www.un.org/en/development/desa/population/publications/pdf/ageing/household_size_and_composition_technical_report.pdf
United Nations, Department of Economic and Social Affairs, Population Division (2022). Database on Household Size and Composition 2022. https://www.un.org/development/desa/pd/data/household-size-and-composition
Terminology (in order of appearance)
kinship: to be related by blood, marriage, adoption, civil recognition, or other long-term commitment
economy: all the human-made systems that transfer and transform energy and matter to meet human needs and wants
extended family: a family which extends beyond parents and children to include grandparents and other relatives
nuclear family: a family of parents and children only
urbanisation: the increase in the proportion of people living in towns and cities, along with the built environment
income: money received from work or investments
values: ideas about what is important or good
household composition: who lives in a household
fertility rate: the average number of children that are born to a woman over her lifetime
care: the act of providing what is necessary for the health, welfare, upkeep, and protection of someone or something
pension: money paid under given conditions to a person following retirement or to surviving dependents
social security: financial and other assistance from the state for people in need
demographic transition: the change in population size or composition over time
birth rate: the ratio of births to the population of a particular area or during a period of time
death rate: the ratio of deaths to the population of a particular area or during a period of time
demographic transition model: a model that explains why countries go through a period of rapid population growth, followed by stabilisation and possible decline
limiting factor: a factor that limits a population or humans, other organisms or things
predator: an animal that eats other animals
sanitation: conditions supporting public health, especially clean drinking water and sewage disposal
gender equality: when people of different genders are treated equally
planetary boundaries: the limits of Earth systems to absorb the impact of human activity and continue to function
matter: anything that takes up space and has mass
energy: the ability to do work or cause change
carbon dioxide (CO2): gas produced by burning carbon or organic compounds and through respiration, naturally present in the atmosphere and absorbed by plants in photosynthesis
ecosystem: the interaction of groups of organisms with each other and their physical environment
biodiversity: the variety of living organisms on Earth
autonomy: freedom from external control or influence; independence
social cohesion: the extent to which people in society feel connected to one another and share common values
domestic worker: someone who lives inside a household and is paid to care for others but is not related to them
efficiency: the ratio of resource inputs compared to outputs
co-living: when people live together who are not related
resilient: able to recover after a disturbance
regenerative economy: an economic system that meets human needs in a way that strengthens social and ecological systems