Somewhere around 2007 the world quietly passed a milestone: for the first time, more people lived in towns and cities than outside them. That shift was driven by people choosing to move, people being forced to move, and cities simply having more births than deaths. This page separates those causes, because exam questions almost always turn on telling them apart.
📚 What you need to know
Urbanisation is a rising proportion of a population living in urban areas.
Urban populations grow through rural-urban migration, natural increase in the city, and boundaries being redrawn.
Push factors drive people out of rural areas; pull factors attract them to cities.
Rural-urban migration is mostly internal, within one country.
Voluntary migration is a choice; forced migration is not.
Countries follow an urbanisation pathway: low, then rapid, then levelling off, then possible counter-urbanisation.
Urbanisation level and urban growth rate are different measures and are constantly confused.
The moment the world became urban
In 1950 roughly 30% of people lived in urban areas. Today it is around 56%, or about 4.4 billion people, and it is still climbing. The graph below shows why that number changed: the urban line rose steeply while the rural line flattened and then began to fall.
Read the axis carefully. This graph shows numbers of people; the urbanisation level is a percentage and behaves differently.
Three ways a city gains people
🧩 Where urban growth actually comes from
Rural-urban migration. People move in from the countryside. Dominant in the early, rapid phase of urbanisation.
Natural increase. Migrants are mostly young adults, so cities have many births and few deaths. In many fast-growing cities this now adds more people than migration does.
Reclassification. The city boundary is redrawn, or a village passes the threshold and is counted as urban. Nobody moved at all.
Point three is the one almost nobody mentions, and it is worth a mark. A country’s urban population can jump overnight because a statistics office changed a definition. It is also why urbanisation figures between countries are not perfectly comparable.
Push and pull
Push factors make the countryside hard to stay in. Pull factors make the city look attractive. In practice both operate at once, and the same person is usually pushed and pulled at the same time.
Note the last pull factor. People move towards an expectation, and the gap between expectation and reality is what fills informal settlements.
Voluntary and forced
Voluntary migration is a decision: someone weighs up the push and pull and chooses to move for work or study. Forced migration removes the choice — war, famine or disaster. People fleeing the conflict in Syria and arriving in urban areas of Turkey and Jordan are the standard example.
The line is not always clean. If a farm fails after three years of drought and the family moves to the city to survive, is that voluntary? Technically yes, since nobody made them go. In practice the choice had already been removed. Saying this shows genuine understanding.
The urbanisation pathway
Countries follow a broadly similar route as they develop, and it maps neatly onto the demographic transition you met in 8.1.
Stage
Urbanisation level
What is happening
Typical example
Developing
Low, under about 25%
Mostly rural, subsistence farming, little industry
Growth continues but starts to slow; suburbs spread outwards
India, Indonesia
Developed
High, 75% or more
Most people already urban, so the level cannot rise much further
United Kingdom, Japan
Counter-urbanising
High but flat or falling
People move out to smaller towns and rural areas
Parts of the USA and western Europe
Level against growth rate
This distinction is examined often and answered badly. Urbanisation level is the percentage of people who are urban. Urban growth rate is how fast the urban population is increasing.
The UK has a very high level (around 84%) but a low growth rate, because its cities were built long ago and there are hardly any rural people left to move in. Nigeria has a much lower level (around half) but a very high growth rate, because it is building its cities right now. High level and high growth are almost opposites.
WORKED EXAMPLE
A country of 40 million people had 12 million urban residents in 2005 and 22 million in 2025. Calculate the urbanisation level in 2025 and the percentage increase in urban population, assuming the total population is now 50 million.
Step 1: urbanisation level in 2025(22 ÷ 50) × 100 = 44Urbanisation level = 44%Step 2: increase in urban population22 − 12 = 10 million(10 ÷ 12) × 100 = 83.3Urban population grew by about 83%Step 3: comment
Fewer than half the people are urban, yet the urban population has almost doubled in twenty years.
A moderate level with a very high growth rate is the signature of a country in the middle of urbanising.
WORKED EXAMPLE
Explain why a city’s population can keep growing rapidly even after rural-urban migration into it has slowed down.
Step 1: who migrates
Migrants are mostly young adults of reproductive age.
Step 2: what that does to the city’s age structure
The city gains a large group of potential parents and relatively few elderly people, so births are high and deaths are low.
Step 3: resultNatural increase takes over from migration as the main source of growth.
Growth continues through natural increase, not arrivalsThis is urban population momentum, and it links straight back to the momentum work in 8.1.
Counter-urbanisation and deurbanisation
The arrow can point the other way. People move out of cities when congestion, cost of housing and pollution outweigh the advantages, when rural areas gain better services, and when technology — particularly remote working — removes the need to live near an office. This is counter-urbanisation, and it is mostly a feature of wealthy countries with already-high urbanisation levels.
💡 Exam tip
Define urbanisation as a rising proportion, not simply “more people in cities”.
Give all three sources of urban growth. Reclassification is the one that separates strong answers.
Push and pull should be given in matched pairs: no jobs in the village, jobs in the city.
State that rural-urban migration is usually internal.
Never mix up urbanisation level with urban growth rate. Say which one the data shows.
When describing a graph, quote a starting value, an ending value and the year of any crossover.
⚠ Common mix-ups
Assuming all urban growth is migration. Natural increase is often the bigger share in fast-growing cities.
Treating high urbanisation as a sign of wealth. Some of the fastest urbanising countries are among the poorest.
Listing push factors as pull factors. Push is why you leave; pull is why you choose that destination.
Believing counter-urbanisation is happening everywhere. It is limited to countries that are already heavily urbanised.
Saying rural populations are collapsing worldwide. The global rural total is roughly flat; it is the urban total that is rising.
Ignoring that “urban” is defined differently in different countries. It makes international comparison rough.
Up next: Urban Sprawl and Expansion — what happens to the land, water and air when all those extra people need somewhere to live.
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