When you walk down a busy high street in the capital today, you are experiencing one of the most rapid demographic transformations in UK history. Between 2001 and 2021, London's total population grew by roughly , rising from to people. Geographers compare recent census figures against baseline data from the 2001 Census to track these changes in age, sex, and ethnicity.
Population structure refers to the makeup of a population by age and sex, often visualised using a population pyramid. London has an unusually young population; its median age is 35, whereas the average for England and Wales is 40. This younger profile is partly due to , where older groups and families move out of the city to the Home Counties.
There is a significant "bulge" in the core working-age group of 25–34-year-olds in London. In 2001, this age bracket made up of the population, but by 2021, they accounted for of Inner London's residents. Conversely, people over 65 represent only of Londoners, compared to nationally, meaning London does not follow the national ageing population trend.
Ethnic diversity measures the variety of different ethnic groups within a population, based on country of birth, religion, or self-identified ethnicity. The proportion of people identifying as White British decreased dramatically from in 2001 to in 2021. In fact, in 2011, White British people became a minority in London for the first time.
Other ethnic groups experienced significant growth during this period:
By 2021, of Londoners were born outside the UK, a sharp rise from in 2001. This represents approximately million people, with the top countries of birth being India, Romania, and Poland. These shifts reflect London's status as a global hub for migration and economic opportunity.
The high concentration of young migrants arriving for work directly impacts London's birth and death rates. Natural increase is the amount by which the birth rate exceeds the death rate. In London, this is particularly high because the young age structure leads to low death rates and a high proportion of women of child-bearing age.
Students often confuse the 'White Other' census category with non-white minority groups. 'White Other' in the UK largely represents European migrants, such as those who arrived after the 2004 EU enlargement.
When outlining demographic change, always quote specific data from two different years (e.g., comparing 2001 and 2021) to prove that a shift has occurred.
In extended response questions on this topic, examiners expect you to explicitly link changes in population structure (such as the bulge in 25–34-year-olds) to specific economic drivers like London's status as a global financial hub.
Remember that migration impacts natural increase as well; migrant populations are typically younger, which raises the birth rate and keeps the death rate low.
Baseline data
The starting point or initial measurements used for comparison, such as the data collected during the 2001 Census.
Population structure
The composition of a population by age and sex, typically visualised using a population pyramid.
Counter-urbanisation
The movement of people, such as older groups and families, out of a city to surrounding rural areas or home counties.
Sex ratio
The number of males per 100 females, or the percentage split of males versus females, within a population.
Ethnic diversity
The presence of different ethnic groups within a population, measured by country of birth, religion, or self-identified ethnicity.
Natural increase
The amount by which the birth rate exceeds the death rate in a population.
Put your knowledge into practice — try past paper questions for Geography B
Baseline data
The starting point or initial measurements used for comparison, such as the data collected during the 2001 Census.
Population structure
The composition of a population by age and sex, typically visualised using a population pyramid.
Counter-urbanisation
The movement of people, such as older groups and families, out of a city to surrounding rural areas or home counties.
Sex ratio
The number of males per 100 females, or the percentage split of males versus females, within a population.
Ethnic diversity
The presence of different ethnic groups within a population, measured by country of birth, religion, or self-identified ethnicity.
Natural increase
The amount by which the birth rate exceeds the death rate in a population.