What Consequences Does the Worldwide Growth of Cities Have for Migration Conditions?

Skyline of Shanghai. (© picture alliance/Eventpress )

Development of "mega-" and "metacities"

According to UN data, in 2008 the number of urbanites worldwide surpassed that of the rural population. It is likely that in 2050 more than two-thirds (72%, or 6.3 billion) of the earth’s population will live in cities [1]. Around 1900, 9 of 10 of the world’s largest cities were in Europe and the USA. However, since the middle of the 20th century, urbanization has boomed around the world, meaning that the urban population, particularly in "third world" countries, dramatically increased. In 1950 there were only two cities in the world that had more than 10 million inhabitants each. Today there are 23 such "megacities", 5 of which are in the "Global North" and 18 in developing or emerging countries. In all likelihood there will be 14 more of these agglomerations by 2025 (cf. Table 2) [2].The development of gigantic "mega-regions" (or "metacities") is already well advanced. These regions are defined as urban areas with more than 20 million inhabitants. They result either from the merging of individual megacities together or from a megacity merging with a metropolitan region in the area. By the year 2015, the Japanese mega-region Tokyo-Nagoya-Osaka-Kyoto-Kobe is expected to contain 60 billion people (the distance from Tokyo to Kobe covers almost 430 km; more than a quarter of the Japanese population live in Tokyo, with almost half in this mega-region). In Brazil a metropolis agglomeration belt stretches from São Paulo to Rio de Janeiro with around 43 million inhabitants and the Chinese mega-region Hongkong-Shenzhen-Guangzhou has an astonishing population of 120 million. Especially characteristic of mega-regions is their economic capacity: 40 of the largest city concentrations contain less than 18 percent of the world’s population, but make up two-thirds of the worldwide economic activity and excel in technological and scientific innovations [3].

Table 2:
Development of City Agglomerations with more than 10 Million Inhabitants 2011
Population (millions)Average annual rate of change (percentage)
The author’s own representation based on data from UN World Urbanization Prospects. The 2011 Revision.
AfricaLagos (Nigeria)1,44,811,218,96,084,08 3,71
Cairo (Egypt)5,69,111,214,72,421,001,98
Asia Tokyo (Japan)23,332,537,238,71,67 0,640,27
Delhi (India)3,59,722,732,95,074,032,67
Shanghai (China)6,07,820,228,41,304,522,43
Mumbai (India)5,812,419,726,63,802,202,12
Beijing (China)4,46,815,622,62,143,962,66
Dhaka (Bangladesh)1,46,615,422,97,864,022,84
Calcutta (India)6,910,914,418,72,261,331,87
Karachi (Pakistan)3,17,113,920,24,153,162,68
Manila (Philippines)3,58,011,916,34,071,892,26
Osaka – Kobe (Japan)9,411,011,512,00,800,190,33
Guangzhou (China)1,53,110,815,53,456,012,54
Shenzhen (China)0,00,910,615,518,4411,892,71
North AmericaNew York - Newark (USA)16,216,120,423,6-0,031,121,05
Los Angeles – Long Beach – Santa Ana (USA)8,410,913,415,71,310,991,13
Latin America Mexico-City (Mexico)8,815,320,424,62,791,381,32
São Paulo (Brazil)7,614,819,923,23,311,421,08
Buenos Aires (Argentina)8,110,513,515,51,301,200,98
Rio de Janeiro (Brazil)6,9,612,013,61,841,050,93
EuropeMoscow (Russian Federation)7,19,011,612,61,171,220,56
Istanbul (Turkey)2,86,611,314,94,302,582,00
Paris (France)8,29,310,612,20,640,62 0,97

Urbanization in regional perspective

However, small and middle-sized cities under 500,000 inhabitants will grow considerably faster than megacities [4]. Four-fifths of the worldwide rise in urban populations will take place in Africa and Asia by 2030, doubling in size from 1.7 to 3.4 million. The largest part of the population by far will also continue to live in less developed countries whose urban population is expected to double between now and 2050, according to UN estimations from 2.6 to 5.2 million people. How rapid the growth of the urban population in past decades took place or will take place in the future is illustrated by some data for the African population: In 1910, the number of Africans living in cities amounted to only 4 million, but by 2007 had climbed to 373 million, and will likely reach 770 million by 2030 [5].

Figure 5: Share of Urban Population according to Region Lizenz: cc by-nc-nd/3.0/de/ (bpb)

A large share of the city and urban agglomerations that grew in Africa, Asia or South America did so unplanned in past decades. The infrastructure (streets, water supply and disposal systems, electricity, and waste disposal) has developed for the most part less dynamically than the size of the urban population. Large social issues and the erection of slums have accompanied this process. Slums are defined as informal, mostly overpopulated settlements characterized by precarious building structures, poorly built infrastructure, and limited protection from weather conditions and intruders. At present, it is likely that almost one billion people live in slums worldwide, with vast differences in distribution across regions of the world. Notably in sub-Saharan Africa more than two-thirds of the people living in cities are classed as slum inhabitants, and a rate of two-fifths is assumed for Asia [6]. However, cities will continue to offer attractive immigration destinations for many people in the future. They are centers of economic growth and innovation, offering varied and plentiful employment opportunities in both the formal and informal sectors, the health system is generally better, as well as the offer of goods for daily needs or education opportunities [7]. Because of this, in addition to natural population growth, the growth of cities will be to a large extent a result of rural-urban migration [8].

Rural-urban migration in the example of China

To what extent the accelerated integration of an economy into the world market can impact the growth of cities, rural-urban migration and intra- and interregional migration is shown in the example of the People’s Republic of China. In 1976, as the founder figure of the People’s Republic died with Mao Zedong, 82% of the total population lived in rural districts. The economic revolution began in the 1980s, which linked the gradual introduction of market economy elements with the opening to the world market and ever more strongly supported exports as a driver for growth. The rapid industrialization of the country led to rapid urbanization. In 2009, the share of city inhabitants had already reached 46 percent (620 million). In 2011, for the first time, more than half of China’s population lived in cities. However, many of the new city dwellers were only tolerated because they were seen as indispensible laborers. They did, however, not have the necessary permission to migrate to and live in a city [9]. In 2007, 46.5 percent of all employed people in cities were labor migrants from rural districts. For the most part the rural-urban migrants were of prime working age, only a small amount was over the age of forty. According to census data, the number of rural-urban migrants stood at 221 million in the year 2010 [10].They predominately worked in the manufacturing, construction, trade and restaurant trades—conversely, the concentration of migrants in such sectors meant a monopolization of specific gainful employment sectors by rural-urban labor migrants. According to the 2000 census data, 80 percent of the workforce in the construction industry and 68 percent of those in the manufacturing industry were labor migrants from other regions.

The direction of migration movements has not changed considerably since the 1990s. Migration destinations for those domestically relocating are the mega-urban regions in the Pearl River Delta which stretch along the Chinese east coast, including Shanghai, the Yangzi Delta and the Peking-Tianjin region. The provinces that attract most of the internal migrants are Guangdong, Zhejiang, Jiangsu and Shandong [11]. In 2004, the southeast Chinese province of Guangdong alone took on around 28 percent of all labor migrants [12]. These people made up almost 43 percent of the province’s total population [13]. There is contradictory data on the composition of rural-urban migration: Males appear to have long shaped interregional migration movements, but since the middle of the first decade of the 21st century the share of females has increased. Yet the share of men still accounts for two-thirds [14]. Because the working population generally migrates, their children often remain in the place of origin under the care of relatives. According to new estimations, the number of children left behind amounts to 58 million – an important social phenomenon that has recently become less important because labor migrants tend to take their children along with increasing frequency into cities where they have better educational opportunities [15].

Rural-urban labor migrants are furthermore also employed for the most part in informal sectors of the labor market which remain characterized by high health risks, heavy physical exertion and difficult wage conditions. The interregional migrants generally work longer for considerably less money than those in the workforce who permanently reside in cities. To some extent the miserable wage and working conditions are often tolerated by the local authorities to enable the establishment of new companies [16]. Moreover, the labor migrants who are mostly put in contact with employers by relatives or acquaintances also accept these conditions because the wages paid in cities usually far exceed those in the regions of origin and the working conditions in agriculture or in rural small-scale businesses are in no way better.

Many things speak for the scope of interregional migration in China to continue climbing if the regionally highly unequally distributed growth of industry production and services continues. The economic growth in the coastal urban agglomerations depends upon migration from the countryside and smaller cities. The Chinese example illustrates the high economic potential of interregional migration. It has reduced un- and underemployment in past years in some parts of the country [17]. and at the same time provided for regions which had a large urgent need for laborers which could not be covered from within the region with the necessary workforce. Interregional migration has presumably raised the growth of China’s gross domestic product (GDP) by about 16 percent. Furthermore, the Chinese rural-urban migrants sent part of their earnings back to remaining family members. These so-called remittances amounted to US$ 30 billion in the year 2005 alone. In this way they have reduced the worsening of rural poverty and also possibly contributed to the economic upswing in the lesser developed parts of China [18]. It is to be expected that China will increasingly become a destination for international migration, considering the foreseeable stagnation of the Chinese population whose decline will begin in the 2020s, the observable increase of labor costs and the accelerating rise in the level of prosperity which leads to the rapid development of the growth of the middleclass.

This text is part of the policy brief on "Global Migration in the Future".
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Birch/Wachter (2011, p. 3); United Nations Department of Economic and Social Affairs, Population Division (2012b, p. 3).
United Nations Department of Economic and Social Affairs, Population Division (2012b, p. 7).
United Nations Human Settlement Programme (2008, p. 8).
Martine et al. (2008, pp. 6f.).
Fourchard (2011, p. 223).
López Moreno (2011).
Hanna/Hanna (2009); Saunders (2010, p. 23).
For an overview see Zlotnik (2006); Hugo (2006); Cerrutti/Bertoncello (2006).
For further details see Fan (2011); Luo (2012); Gransow (2012).
Gransow (2012, p. 2).
Gransow (2012, p. 3).
Shen (2011).
Junyong (2011, p. 145).
Hussain/Wang (2010, pp. 139-141f.).
Opitz (2011, pp. 24-30); Wing Chan (2011, pp. 91-99).
Fu Keung Wong et al. (2007).
Luo/Yue (2010).
Koser (2011, pp. 167f.).

Jochen Oltmer

Jochen Oltmer

Dr. phil. habil., born 1965, is Associate Professor of Modern History and member of the board of the Institute for Migration Research and Intercultural Studies (IMIS) of the University of Osnabrück, Germany.

The author thanks Vera Hanewinkel, Kristina Jäger and Martha Quis for their extensive research as well as for their many comments and suggestions. Email: joltmer@uni-osnabrueck.de

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