When the World Became Urban

Around 2007 city dwellers outnumbered everyone else for the first time — and the share keeps climbing

Somewhere around 2007, for the first time in human history, more people lived in cities than outside them. The share is now about 57% and still climbing. For roughly 10,000 years since agriculture began, the opposite was true — overwhelmingly so.

How fast it happened

Approximate figures; UN World Urbanization Prospects.

The absolute numbers matter more than the percentages. Urban population grew from 30 million to 4.7 billion in two centuries — a factor of over 150, while total population grew roughly eightfold.

What counts as "urban" is not standardised

An important caveat that rarely gets stated: there is no international definition of a city. Each country sets its own threshold, and they differ wildly.

Some countries classify any settlement above 200 people as urban. Others use 2,000, 5,000, or 20,000. Some add criteria about population density, employment mix, or administrative status. Japan's threshold is among the highest in the world; several Nordic countries use among the lowest.

This means cross-country urbanisation comparisons are shakier than they appear. The global trend is unambiguous and large enough to survive the noise — but a two-point difference between two countries may be a definitional artefact rather than a real one.

Why people move

Urbanisation is driven by both push and pull, and the balance differs by region:

• Agricultural productivity rose. Fewer farmers were needed to feed more people, releasing rural labour. This is the deepest cause.
• Cities concentrate opportunity. Wages, jobs, and educational access are consistently higher in urban areas, even accounting for cost of living.
• Services cluster. Hospitals, universities, and infrastructure are cheaper to provide per person at density.
• Cities grow from within. A large share of urban growth is now natural increase — births to existing urban residents — not migration at all. This is widely underestimated.

Density has a demographic effect

Urbanisation and falling fertility are tightly linked, and the causation runs mostly one way. Urban fertility is consistently lower than rural fertility within virtually every country, often by a full child or more.

The reasons are practical rather than cultural. Urban housing is expensive and constrains family size. Children are an economic cost rather than farm labour. Women's workforce participation and education are higher. Marriage and first birth happen later.

Because of this, urbanisation is one of the more reliable predictors of a country's fertility trajectory. As a country urbanises, its birth rate tends to fall — which is part of why global population is projected to peak this century.

Where the growth is going

Nearly all future urban growth is expected in Asia and Africa. Africa is the least urbanised major region today and is urbanising fastest; its urban population is projected to roughly double by 2050.

The character of that growth differs from the historical European and American pattern. Much of it is happening in secondary cities rather than capitals, and often faster than infrastructure can follow — which is why informal settlement is growing alongside formal urban expansion.

To see how population is distributed geographically today, explore the population density heat map or the country-by-country table.