Megacities

What is a megacity?

A megacity is, according to the definition of the United Nations, a city with more than 10 million inhabitants. Elsewhere, you can find thresholds between five and eight million. To make matters worse, a city is often confused with a metropolitan area. For example, the area known as "Metro Manila" has about 25 million inhabitants and is often referred to as a megacity. But the city of Manila itself has less than two million inhabitants.

Our ranking lists the population of the actual cities with more than five million inhabitants, so no combined metropolitan regions or higher-level government districts.

The concept of a city

The definition of a city is inconsistent at the international level. In the U.S., the concept of city limits or city proper has been established, but it cannot be applied to all other countries. In purely substantive terms, a city refers to a uniformly and centrally administered political area with clearly defined boundaries. In many countries, these city limits are indicated by city signs on the streets. Even in the case of centrally administered rural communities, this is no longer quite so simple, because often several localities belong to the administrative area. In visual terms, they consist of several small towns, and between them there are often large agricultural areas.

It is even more difficult in countries that have a completely different concept of a city. What is understood as a city administration in the USA refers to entire regions elsewhere. Sometimes municipal tasks are combined over a wide area. But if territorial sovereignty is bundled in one place, this corresponds to the actual definition of a city - even if this administration is dozens of miles away.

In the USA in particular, but only a few other countries, the term of the urban area exists alongside the term "city proper". It came into being because the visual appearance of a city often deviates far from the administrative city limits. For example, New York City has about 8 million inhabitants within the city limits, but more than twice of it in the urban area.

The term "city" is therefore interpreted differently from country to country, and only rarely are population figures precisely ascertainable. In Canada, Thailand, Switzerland or even Colombia, one speaks of agglomerations, which are formed for statistical purposes and also include surrounding areas. The EU tries to use the term "functional urban area", which may also include additional areas besides the urban core. But even these two terms cannot be applied to all countries. Japan, for example, has created a separate unit only for Tokyo, because the city does not fit into any of the common patterns.

In order to make city sizes comparable, the United Nations is trying to establish the concept of an "urban agglomeration", i.e. a coherent urban area. According to this scheme, the city of Tokyo would have 39 million inhabitants, while the actual urban area has only about 14 million. If one were to apply this consideration to other countries, numerous large cities such as Fort Worth near Dallas or more than 2 dozen cities around Los Angeles would no longer exist because they would be absorbed into the agglomeration of another city.

The bottom line is that it remains difficult to determine the size of cities in a uniform way.

Megacities in China

Among the 85 largest cities in the world, China is represented 47 times. This may seem somewhat unfair, as large cities are "constructed" there disproportionately often. Normally, cities grow and shrink through natural urbanization. However, political decisions - especially in China - often result in cities being merged that were previously located next to each other and existed separately. This creates a common municipal legal structure with a unified administration, which from a political perspective leads to a city. However, as these Chinese "cities" can contain not only districts, but also other towns and administrative districts, they are more comparable to what is called a county or administrative district in other countries.

The Chinese government is currently planning to merge the megacity of Shanghai with 8 surrounding cities to create the planned city of "Jing-Jin-Ji" with 130 million inhabitants. Another super city with a planned population of 40 million is to be built by 2030 on the Pearl River Delta north of Hong Kong around the current cities of Shenzhen and Guangzhou.

According to current plans, there will be more than 200 planned cities with over 1 million inhabitants in the coming years.