Primate City

Have you heard of megacities? What about metacities? Global cities? Capital cities? It's likely these cities can also be primate cities. These are cities that are considerably larger than other cities within a country. In the US, we have a collection of different-sized cities scattered around the nation. This can make it difficult to imagine a city so large and prominent that it can influence most of a country. But it's possible! Let's explore primate cities, common characteristics, and some examples.

Primate City Definition

Primate cities have the highest population of an entire country, hosting at least twice the population of the second largest city. Primate cities are usually highly-developed and major functions (economic, political, and cultural) are performed there. Other cities in the country tend to be smaller and less developed, with most national focus revolving around the primate city. The primate city rule is primarily a theory before it is a rule.

There are numerous reasons why primate cities develop instead of following the rank-size rule. This can depend on socioeconomic factors, physical geography, and historical events. The primate city concept is meant to explain why some countries have one major city, whereas other countries have smaller cities scattered around their country.

Primate City Rule

Mark Jefferson re-iterated urban primacy as the primate city rule in 1939¹:

Essentially, a primate city is considerably larger and more influential than any other city within a country. Jefferson argued that a primate city has the greatest national influence, and 'unifies' the country together. For a primate city to be achieved, a country had to reach a level of 'maturity' to attain the level of regional and global influence.

It's important to note, Jefferson was not the first geographer to theorize a primate city rule. Geographers and scholars before him attempted to understand the complexity of countries and cities at a time of limited technology and increasingly complex economic, social, and urban phenomena.

At the time, Jefferson's rule was applied to developed countries, with the exception of the US. Many geographers afterward attributed the primate city rule to developing countries, albeit more negatively. Whereas it was believed to be a positive thing before the 1940s, a harsher narrative began when describing rising population growth in cities of the developing world. The primate city concept was sometimes used to justify racist attitudes of the time.

Characteristics of a Primate City

Common characteristics of a primate city included patterns seen in most large, dense cities. Countries have changed dramatically since these characteristics have been set. However, they can generally be attributed to major cities in developing countries.

A primate city will have a very large population in comparison to other cities within the country, and may even be considered a megacity or metacity globally. It will have a well-established transportation and communication system that aims to connect all parts of the country to the city. It will be a hub for major businesses, with most financial institutions and foreign investment concentrated there.

A primate city is similar to other major capital cities in that it can provide educational and economic opportunities that other parts of the country cannot. A city is considered a primate city when it's compared to other towns and cities within the country. If it's strikingly larger and more influential, it's likely a primate city.

Fig. 1 - Seoul, South Korea; Seoul is an example of a Primate City

Rank Size Rule vs Primate City

The primate city concept is usually taught alongside the rank-size rule. This is because the distribution and size of cities vary not only between countries but also between different time periods. Whereas Europe and North America experienced industrialization, urbanization, and population growth earlier (the late 1800s), other countries and regions in the world experienced these developments later (the mid-1900s).

The rank-size rule is based on George Kingsley Zipf's power distribution theory. Essentially it states that in some countries, cities can be ranked from largest to smallest, with a predictable rate of decrease in size. For instance, let's say the largest city's population is 9 million. The second largest city would then have about half of that or 4.5 million. The third largest city would then have 3 million people (a 1/3rd of the population), and so on.

Criticisms of the Primate City

There are several criticisms both of primate cities themselves, as well as the theory behind them. While primate cities have a lot of influence within their respective countries, this can lead to political and economic marginalization.⁴ As the focus of development is placed primarily on the primate city, other areas of a country may be neglected. This can be detrimental to ongoing development in a country.

The theory behind the primate city was published during a time when many colonies were just gaining independence. Many countries began industrializing and experiencing population growth in major cities. Jefferson's theory primarily discussed the maturity and influence of major cities in industrialized countries such as London, Paris, and Moscow.⁵ However, the timing of his theory alongside the independence of European colonies shifted the discussion. Over time, new associations of the primate city were applied to developing countries, with more negative characteristics. This has changed the definition of the primate city, with a lack of consensus on the negatives, positives, and overall characteristics of this theory.

Primate City Example

There are several notable examples of primate cities worldwide, both in developed and developing countries. The major differences between primate cities have to do with when they were established, over which period of time cities grew and urbanized, and the leading causes for expansion.

Primate City of the UK

The UK's primate city is London, with a population of over 9.5 million. The second largest city in the UK is Birmingham, with a population of just over 1 million. The rest of the cities in the UK largely hover below a million, disqualifying the UK from following the rank-size rule.

Fig. 2 - London, UK

London is known for its international influence in business, education, culture, and recreation. It hosts the location of many international headquarters, as well as a diverse set of businesses and services in the quaternary sector.

London's initial growth and urbanization arose from rapid immigration beginning in the 1800s. Although it has slowed significantly, London is still a major hub for international migrants and provides many opportunities for people looking for new opportunities or a higher quality of life.

Given the absence of cars for centuries, London is very dense. However, with continued growth, suburban sprawl has become an issue. A lack of housing affordability is fueling this development, contributing to deteriorating air quality levels as more cars need to enter the city from outside the urban core.

Primate City of Mexico

A notable case of a primate city is Mexico City, Mexico. The city itself has a population of around 9 million people, while the greater metropolitan area as a whole has a population of around 22 million. Previously known as Tenochtitlan, it was the host of one of the earliest known civilizations in the Americas, the Aztecs. Mexico has experienced major conquests and wars between both European powers and the US in the last few centuries, with Mexico City as the center for most of these conflicts.

Mexico City's explosion in population size started after WWII, as the city began investing in the construction of universities, metro systems, and supporting infrastructures. Both local and international industries began building factories and headquarters in and around Mexico City. By the 1980s, most higher-paying jobs in Mexico were located in Mexico City, creating an ever-increasing incentive to move toward the capital.

Fig. 3 - Mexico City, Mexico

The location of Mexico City within a valley complicates both its growth and environmental state. Previously, Tenochtitlan was built along a series of small islands within Lake Texcoco. Lake Texcoco has been draining steadily as the city continues to expand. Unfortunately, with groundwater depletions, the ground is experiencing both sinking and flooding, causing hazards for residents. Compounded with rapid industrialization and urbanization within the Valley of Mexico, both air and water quality levels have fallen.