17.3: Urbanization and the Development of Cities

The Earliest Cities

Early cities arose in a number of regions, and are thought to have developed for reasons of agricultural productivity and economic scale.

Learning Objectives

Summarize the various beginnings of cities, from centers of agriculture to areas of protection, and the factors they need to be successful

Key Points

• The very first cities were founded in Mesopotamia after the Neolithic Revolution, around 7500 BCE.
• Agriculture is believed to be a pre-requisite for cities, which help preserve surplus production and create economies of scale.
• Cities reduced transport costs for goods, people, and ideas by bringing them all together in one spot.

Key Terms

• Old World: The known world before the discovery of the Americas.
• Neolithic Revolution: The Neolithic Revolution or Neolithic Demographic Transition, sometimes called the Agricultural Revolution, was the world’s first historically verifiable revolution in agriculture.
• urbanism: the study of cities, their geographic, economic, political, social, and cultural environment

Early cities developed in a number of regions, from Mesopotamia to Asia to the Americas. The very first cities were founded in Mesopotamia after the Neolithic Revolution, around 7500 BCE. Mesopotamian cities included Eridu, Uruk, and Ur. Early cities also arose in the Indus Valley and ancient China. Among the early Old World cities, one of the largest was Mohenjo-daro, located in the Indus Valley (present-day Pakistan); it existed from about 2600 BCE, and had a population of 50,000 or more. In the ancient Americas, the earliest cities were built in the Andes and Mesoamerica, and flourished between the 30^th century BCE and the 18^th century BCE.

Ancient cities were notable for their geographical diversity, as well as their diversity in form and function. Theories that attempt to explain ancient urbanism by a single factor, such as economic benefit, fail to capture the range of variation documented by archaeologists. Excavations at early urban sites show that some cities were sparsely populated political capitals, others were trade centers, and still other cities had a primarily religious focus. Some cities had large dense populations, whereas others carried out urban activities in the realms of politics or religion without having large associated populations. Some ancient cities grew to be powerful capital cities and centers of commerce and industry, situated at the centers of growing ancient empires. Examples include Alexandria and Antioch of the Hellenistic civilization, Carthage, and ancient Rome and its eastern successor, Constantinople (later Istanbul).

The Formation of Cities

Why did cities form in the first place? There is insufficient evidence to assert what conditions gave rise to the first cities, but some theorists have speculated on what they consider pre-conditions and basic mechanisms that could explain the rise of cities. Agriculture is believed to be a pre-requisite for cities, which help preserve surplus production and create economies of scale. The conventional view holds that cities first formed after the Neolithic Revolution, with the spread of agriculture. The advent of farming encouraged hunter-gatherers to abandon nomadic lifestyles and settle near others who lived by agricultural production. Agriculture yielded more food, which made denser human populations possible, thereby supporting city development. Farming led to dense, settled populations, and food surpluses that required storage and could facilitate trade. These conditions seem to be important prerequisites for city life. Many theorists hypothesize that agriculture preceded the development of cities and led to their growth.

A good environment and strong social organization are two necessities for the formation of a successful city. A good environment includes clean water and a favorable climate for growing crops and agriculture. A strong sense of social organization helps a newly formed city work together in times of need, and it allows people to develop various functions to assist in the future development of the city (for example, farmer or merchant). Without these two common features, as well as advanced agricultural technology, a newly formed city is not likely to succeed.

Cities may have held other advantages, too. For example, cities reduced transport costs for goods, people, and ideas by bringing them all together in one spot. By reducing these transaction costs, cities contributed to worker productivity. Finally, cities likely performed the essential function of providing protection for people and the valuable things they were beginning to accumulate. Some theorists hypothesize that people may have come together to form cities as a form of protection against marauding barbarian armies.

Preindustrial Cities

Preindustrial cities had important political and economic functions and evolved to become well-defined political units.

Learning Objectives

Examine the growth of preindustrial cities as political units, as well as how trade routes allowed certain cities to expand and grow

Key Points

• Preindustrial cities were political units, like today’s states. They offered freedom from rural obligations to lord and community.
• In the early modern era, larger capital cities benefited from new trade routes and grew even larger.
• While the city-states, or poleis, of the Mediterranean and Baltic Sea languished from the 16th century, Europe’s larger capitals benefited from the growth of commerce following the emergence of an Atlantic trade.

Key Terms

• lord: A titled nobleman or aristocrat
• rural obligations: For people during the medieval era, cities offered a newfound freedom from rural obligations. City residence brought freedom from customary rural obligations to lord and community.
• Preindustrial cities: While ancient cities may have arisen organically as trading centers, preindustrial cities evolved to become well defined political units.

Cities as Political Centers

While ancient cities may have arisen organically as trading centers, preindustrial cities evolved to become well defined political units, like today’s states. During the European Middle Ages, a town was as much a political entity as a collection of houses. However, particular political forms varied. In continental Europe, some cities had their own legislatures. In the Holy Roman Empire, some cities had no other lord than the emperor. In Italy, medieval communes had a state-like power. In exceptional cases like Venice, Genoa, or Lübeck, cities themselves became powerful states, sometimes taking surrounding areas under their control or establishing extensive maritime empires. Similar phenomena existed elsewhere, as in the case of Sakai, which enjoyed a considerable autonomy in late medieval Japan.

For people during the medieval era, cities offered a newfound freedom from rural obligations. City residence brought freedom from customary rural obligations to lord and community (hence the German saying, “Stadtluft macht frei,” which means “City air makes you free”). Often, cities were governed by their own laws, separate from the rule of lords of the surrounding area.

Trade Routes

Not all cities grew to become major urban centers. Those that did often benefited from trade routes—in the early modern era, larger capital cities benefited from new trade routes and grew even larger. While the city-states, or poleis, of the Mediterranean and Baltic Sea languished from the 16^th century, Europe’s larger capitals benefited from the growth of commerce following the emergence of an Atlantic trade. By the early 19^th century, London had become the largest city in the world with a population of over a million, while Paris rivaled the well-developed regional capital cities of Baghdad, Beijing, Istanbul, and Kyoto. But most towns remained far smaller places—in 1500 only about two dozen places in the world contained more than 100,000 inhabitants. As late as 1700 there were fewer than 40, a figure which would rise thereafter to 300 in 1900. A small city of the early modern period might have contained as few as 10,000 inhabitants.

Industrial Cities

During the industrial era, cities grew rapidly and became centers of population growth and production.

Learning Objectives

Discuss the problems urbanization created for newly formed cities

Key Points

• Rapid growth brought urban problems, and industrial-era cities were rife with dangers to health and safety.
• Poor sanitation and communicable diseases were among the greatest causes of death among urban working class populations.
• In the 19th century, better sanitation led to improved health conditions.

Key Terms

• industrial cities: Rapid growth brought urban problems, and industrial-era cities were rife with dangers to health and safety. Quickly expanding industrial cities could be quite deadly, full of contaminated water and air, and communicable diseases.
• industrial era: During the industrial era, cities grew rapidly and became centers of population and production.

Slum in Glasgow, 1871: An example of slum life in an industrial city.

During the industrial era, cities grew rapidly and became centers of population and production. The growth of modern industry from the late 18^th century onward led to massive urbanization and the rise of new, great cities, first in Europe, and then in other regions, as new opportunities brought huge numbers of migrants from rural communities into urban areas. In 1800, only 3% of the world’s population lived in cities. Since the industrial era, that figure, as of the beginning of the 21^st century, has risen to nearly 50%. The United States provides a good example of how this process unfolded; from 1860 to 1910, the invention of railroads reduced transportation costs and large manufacturing centers began to emerge in the United States, allowing migration from rural to urban areas.

Rapid growth brought urban problems, and industrial-era cities were rife with dangers to health and safety. Rapidly expanding industrial cities could be quite deadly, and were often full of contaminated water and air, and communicable diseases. Living conditions during the Industrial Revolution varied from the splendor of the homes of the wealthy to the squalor of the workers. Poor people lived in very small houses in cramped streets. These homes often shared toilet facilities, had open sewers, and were prone to epidemics exacerbated by persistent dampness. Disease often spread through contaminated water supplies.

In the 19^th century, health conditions improved with better sanitation, but urban people, especially small children, continued to die from diseases spreading through the cramped living conditions. Tuberculosis (spread in congested dwellings), lung diseases from mines, cholera from polluted water, and typhoid were all common. The greatest killer in the cities was tuberculosis (TB). Archival health records show that as many as 40% of working class deaths in cities were caused by tuberculosis.

The Structure of Cities

Urban structure is the arrangement of land use, explained using different models.

Learning Objectives

Analyze, using human ecology theory, the similarities and differences between the various urban structure models, such as grid model, sectoral model and concentric ring model, among others

Key Points

• In the grid model of cities, land is divided by streets that run at right angles to each other, forming a grid. This model promotes development.
• The concentric ring model describes the city as an ecosystem in which residents sort themselves into a series of rings based on class and occupation. This model’s general applicability has been challenged.
• Urban structure can also describe the location of the central business district, industrial parks, or urban open spaces.
• The sectoral model says the city develops in wedge-shaped sectors instead of rings: certain areas of a city are more attractive for various activities, which flourish and expand outward in a wedge.
• The multiple nuclei model assumes that car ownership granted people more mobility and led the the development of specialized regional centers within cities.
• The irregular pattern model was developed to better explain urban structure in the Third World. It attempts to model the lack of planning or construction found in many rapidly built Third World cities.

Key Terms

• central business district: The central area of a city in which a concentration of certain retail and business activities takes place, especially in older cities with rail transportation.
• urban open space: In land use planning, urban open space is open space areas for parks, green spaces, and other open areas.
• Human Ecology: Human ecology described the city as analogous to an ecosystem, with natural processes of adaptation and assimilation.

Urban Structure Models

Grid

In grid models, land is divided by streets intersect at right angles, forming a grid. Grid plans are more common in North American cities than in Europe, where older cities tend to be build on streets that radiate out from a central square or structure of cultural significance. Grid plans facilitate development because developers can subdivide and auction off large parcels of land. The geometry yields regular lots that maximize use and minimize boundary disputes. However, grids can be dangerous because long, straight roads allow faster automobile traffic. In the 1960s, urban planners moved away from grids and began planning suburban developments with dead ends and cul-de-sacs.

Concentric Ring Model

The concentric ring model was postulated in 1924 by sociologist Ernest Burgess, based on his observations of Chicago. It draws on human ecology theories, which compared the city to an ecosystem, with processes of adaptation and assimilation. Urban residents naturally sort themselves into appropriate rings, or ecological niches, depending on class and cultural assimilation. The innermost ring represents the central business district (CBD), called Zone A.. It is surrounded by a zone of transition (B), which contains industry and poorer-quality housing. The third ring (C) contains housing for the working-class—the zone of independent workers’ homes. The fourth ring (D) has newer and larger houses occupied by the middle-class. The outermost ring (E), or commuter’s zone, is residential suburbs.

Toronto’s Central Business District: Skyscrapers populate Toronto’s central business district

Concentric Zone Model: The Concentric Ring Model described the city as a series of concentric rings, each home to a different group and social function.

This model’s general applicability has been challenged. It describes an American geography in which the inner city is poor while suburbs are wealthy—elsewhere, the converse is the norm. In new, western U.S. cities such as Los Angeles, advances in transportation and communication have blurred these “zones. ” Further, the model fails to account for topographical and physical features of the landscape. Even in Chicago, the concentric rings were semi-circles, interrupted by Lake Michigan.

Sectoral

In 1939, the economist Homer Hoyt adapted the concentric ring model by proposing that cities develop in wedge-shaped sectors instead of rings. Certain areas of a city are more attractive for various activities, whether by chance or geographic/environmental reasons. As these activities flourish and expand outward, they form wedges, becoming city sectors. Like the concentric ring model, Hoyt’s sectoral model has been criticized for ignoring physical features and new transportation patterns that restrict or direct growth.

Hoyt’s Sectoral Model of Urban Growth: In Hoyt’s model, cities grow in wedge-shaped sectors radiating from the center.

Multiple Nuclei

The multiple nuclei model was developed in 1945 to explain city formation after the spread of the automobile. People have greater movement due to increased car ownership, allowing for the specialization of regional centers. A city contains more than one center around which activities revolve. Some activities are attracted to particular nodes while others try to avoid them. For example, a university node may attract well-educated residents, pizzerias, and bookstores, whereas an airport may attract hotels and warehouses. Incompatible activities will avoid clustering in the same area.

Irregular Pattern

The irregular pattern model was developed to explain urban structure in the Third World. It attempts to model the lack of planning found in many rapidly built Third World cities. This model includes blocks with no fixed order; urban structure is not related to an urban center or CBD.

Alternate Uses of “Urban Structure”

Urban structure can also refer to urban spatial structure; the arrangement of public and private space in cities and the degree of connectivity and accessibility. In this context, urban structure is concerned with the arrangement of the CBD, industrial and residential areas, and open space.

A city’s central business district (CBD), or downtown, is the commercial and often geographic heart of a city. In North America, this is referred to as “downtown” or “city center. ” The downtown area is often home to the financial district, but usually also contains entertainment and retail. CBDs usually have very small resident populations, but populations are increasing as younger professional and business workers move into city center apartments.

An industrial park is an area zoned and planned for the purpose of industrial development. They are intended to attract business by concentrating dedicated infrastructure to reduce the per-business expenses. They also set aside industrial uses from urban areas to reduce the environmental and social impact of industrial uses and to provide a distinct zone of environmental controls specific to industrial needs.

Urban open spaces provide citizens with recreational, ecological, aesthetic value. They can range from highly maintained environments to natural landscapes. Commonly open to public access, they may be privately owned. Urban open spaces offer a reprieve from the urban environment and can add ecological value, making citizens more aware of their natural surroundings and providing nature to promote biodiversity. Open spaces offer aesthetic value for citizens who enjoy nature, cultural value by providing space for concerts or art shows, and functional value—for example, by helping to control runoff and prevent flooding.

The Process of Urbanization

Urbanization is the process of a population shift from rural areas to cities, often motivated by economic factors.

Learning Objectives

Analyze the proces of urbanization and its effects on economics and the environment in society

Key Points

• Urbanization may be driven by local and global economic and social changes, and is generally a product of modernization and industrialization.
• Urbanization has economic and environmental effects. Economically, urbanization drives up prices, especially real estate, which can force original residents to move to less-desirable neighborhoods.
• Environmentally, cities cause “heat islands”, where less vegetation and open soil raise city temperatures by 2 to 10 degrees Fahrenheit.
• Recently in developed countries, sociologists have observed suburbanization and counterurbanization, or movement away from cities, which may be driven by transportation infrastructure, or social factors like racism.

Key Terms

• suburbanization: A term used to describe the growth of areas on the fringes of major cities; one of the many causes of the increase in urban sprawl.
• rural flight: A term used to describe the migratory patterns of peoples from rural areas into urban areas.
• urbanization: The physical growth of urban areas as a result of rural migration and even suburban concentration into cities.
• counterurbanization: A demographic and social process whereby people move from urban areas to rural areas.
• gentrification: A shift in an urban community toward wealthier residents and/or businesses and increasing property values; often resulting in poorer residents being displaced by wealthier newcomers.

Urbanization and rural flight

Urbanization is the process of a population shift from rural areas to cities. During the last century, global populations have urbanized rapidly:

• 13% of people lived in urban environments in the year 1900
• 29% of people lived in urban environments in the year 1950

One projection suggests that, by 2030, the proportion of people living in cities may reach 60%.

Rural and Urban World Population: Over time, the world’s population has become less rural and more urban.

Urbanization tends to correlate positively with industrialization. With the promise of greater employment opportunities that come from industrialization, people from rural areas will go to cities in pursuit of greater economic rewards.

Another term for urbanization is “rural flight. ” In modern times, this flight often occurs in a region following the industrialization of agriculture—when fewer people are needed to bring the same amount of agricultural output to market—and related agricultural services and industries are consolidated. These factors negatively affect the economy of small- and middle-sized farms and strongly reduce the size of the rural labor market. Rural flight is exacerbated when the population decline leads to the loss of rural services (such as business enterprises and schools), which leads to greater loss of population as people leave to seek those features.

As more and more people leave villages and farms to live in cities, urban growth results. The rapid growth of cities like Chicago in the late nineteenth century and Mumbai a century later can be attributed largely to rural-urban migration. This kind of growth is especially commonplace in developing countries.

Urbanization occurs naturally from individual and corporate efforts to reduce time and expense in commuting, while improving opportunities for jobs, education, housing, entertainment, and transportation. Living in cities permits individuals and families to take advantage of the opportunities of proximity, diversity, and marketplace competition. Due to their high populations, urban areas can also have more diverse social communities than rural areas, allowing others to find people like them.

A link to the YouTube element can be found in Contributors & Attributions section.

Megacities Reflect Growing Urbanization Trend – YouTube: In the developing world, huge cities with sprawling slums have developed as agriculture and rural occupations have been supplanted by mechanized industries.

Economic and Environmental Effects of Urbanization

Urbanization has significant economic and environmental effects on cities and surrounding areas. As city populations grow, they increase the demand for goods and services of all kinds, pushing up prices of these goods and services, as well as the price of land. As land prices rise, the local working class may be priced out of the real estate market and pushed into less desirable neighborhoods – a process known as gentrification.

Growing cities also alter the environment. For example, urbanization can create urban “heat islands,” which are formed when industrial and urban areas replace and reduce the amount of land covered by vegetation or open soil. In rural areas, the ground helps regulate temperatures by using a large part of the incoming solar energy to evaporate water in vegetation and soil. This evaporation, in turn, has a cooling effect. However in cities, where less vegetation and exposed soil exists, the majority of the sun’s energy is absorbed by urban structures and asphalt. During the day, cities experience higher surface temperatures because urban surfaces produce less evaporative cooling. Additional city heat is given off by vehicles and factories, as well as industrial and domestic heating and cooling units. Together, these effects can raise city temperatures by 2 to 10 degrees Fahrenheit (or 1 to 6 degrees Celsius).

Suburbanization and Counterurbanization

Recently in developed countries, sociologists have observed suburbanization and counterurbanization, or movement away from cities. These patterns may be driven by transportation infrastructure, or social factors like racism. In developed countries, people are able to move out of cities while still maintaining many of the advantages of city life (for instance, improved communications and means of transportation). In fact, counterurbanization appears most common among the middle and upper classes who can afford to buy their own homes.

Race also plays a role in American suburbanization. During World War I, the massive migration of African Americans from the South resulted in an even greater residential shift toward suburban areas. The cities became seen as dangerous, crime-infested areas, while the suburbs were seen as safe places to live and raise a family, leading to a social trend known in some parts of the world as “white flight. ” Some social scientists suggest that the historical processes of suburbanization and decentralization are instances of white privilege that have contributed to contemporary patterns of environmental racism.

In the United States, suburbanization began in earnest after World War II, when soldiers returned from war and received generous government support to finance new homes. Suburbs, which are residential areas on the outskirts of a city, were less crowded and had a lower cost of living than cities. Suburbs grew dramatically in the 1950s when the U.S. interstate highway system was built, and automobiles became affordable for middle class families. Around 1990, another trend emerged known as counterurbanization, or “exurbanization”. The wealthiest individuals began living in nice housing far in rural areas (as opposed to forms).

Suburbanization may be a new urban form.Rather than densely populated centers, cities may become more spread out, composed of many interconnected smaller towns. Interestingly, the modern U.S. experience has gone from a largely rural country, to a highly urban country, to a country with significant suburban populations.

U.S. Urban Patterns

The U.S. Census Bureau classifies areas as urban or rural based on population size and density.

Learning Objectives

Discuss the different ways governments and society define the term “urban”

Key Points

• Different agencies and individuals define urban in different ways, but the U.S. Census Bureau ‘s definitions are considered standard.
• The U.S. Census Bureau defines “urban areas” as areas with a population density of at least 1,000 people per square mile and at least 2,500 total people.
• As of December, 2010, about 82% of the population of the United States lived within the boundaries of urbanized area.

Key Terms

• population density: The average number of people who live on each square mile (or kilometer) of land.

Different international, national, and local agencies may define “urban” in various ways. For example, city governments often use political boundaries to delineate what counts as a city. Other definitions may consider total population size or population density. Different definitions may also set various thresholds, so that in some cases, a town of just 2,500 may count as an urban city, whereas in other contexts, a city may be defined as having at least 50,000 people. Other agencies may define “urban” based on land use: places count as urban if they are built up with residential neighborhoods, industrial sites, railroad yards, cemeteries, airports, golf courses, and similar areas. Using this sort of definition, in 1997, the U.S. Department of Agriculture tallied over 98,000,000 acres of “urban” land.

In spite of these competing definitions, in the United States “urban” is officially defined following guidelines set by the U.S. Census Bureau. The Census Bureau defines “urban areas” as areas with a population density of at least 1,000 people per square mile and at least 2,500 total people. Urban areas are delineated without regard to political boundaries. Because this definition does not consider political boundaries, it is often used as a more accurate gauge of the size of a city than the number of people who live within the city limits. Often, these two numbers are not the same. For example, the city of Greenville, South Carolina has a city population under 60,000 and an urbanized area population of over 300,000, while Greensboro, North Carolina has a city population over 200,000 and an urbanized area population of around 270,000. That means that Greenville is actually “larger” for some intents and purposes, but not for others, such as taxation, local elections, etc.

As of December, 2010, about 82% of the population of the United States lived within the boundaries of urbanized area. Combined, these areas occupy about 2% of the land area of the United States. The majority of urbanized area residents are suburbanites; core central city residents make up about 30% of the urbanized area population (about 60 million out of 210 million). In the United States, the largest urban area is New York City, with over 8 million people within the city limits and over 19 million in the urban area. The next five largest urban areas in the United States are Los Angeles, Chicago, Washington, D.C., Philadelphia, and Boston.

American urban areas by size: This map shows major urban areas in America.

The Rural Rebound

During the 1970s and again in the 1990s, the rural population rebounded in what appeared to be a reversal of urbanization.

Learning Objectives

Explain the rural rebound and how it contributes to the suburbanization of society

Key Points

• Much of the “rural” rebound was driven by suburbanization, which is the movement of people from cities to surrounding suburbs, ex-urbs, or edge cities.
• Suburbanization may be driven by white flight.
• Counterurbanization refers, broadly, to movement away from the city, which may include urban-to-rural migration and suburbanization.
• Counterurbanization has created shrinking cities and attempts to better control urban growth.

Key Terms

• white flight: The large-scale migration of whites of various European ancestries, from racially mixed urban regions to more racially homogeneous suburban areas.
• ex-urbs: The expression exurb (for “extra-urban”) was coined by Auguste Comte Spectorsky in his 1955 book The Exurbanites to describe the ring of prosperous communities beyond the suburbs that are commuter towns for an urban area.
• counterurbanization: Counterurbanisation is a demographic and social process whereby people move from urban areas to rural areas.

The rural rebound refers to the movement away from cities to rural and suburban areas. Urbanization tends to occur along with modernization, yet in the most developed countries many cities are now beginning to lose population. In the United States in the 1970s, demographers observed that the rural population was actually growing faster than urban populations, a phenomenon they labeled the “rural rebound. ” This trend reversed in the 1980s, due in part to a recession that hit farmers particularly hard. But again in the 1990s, rural populations appeared to be gaining at the expense of cities. Indeed, in the last 50 years, about 370 cities worldwide with more than 100,000 residents have undergone population losses of more than 10%, and more than 25% of the depopulating cities are in the United States.

Rather than moving to rural areas, most participants in the so-called the rural rebound migrated into new, rapidly growing suburbs. The rural rebound, then, may be more evidence of the importance of suburbanization as a new urban form in the most developed countries.

Suburbanization

Suburbanization is a general term that refers to the movement of people from cities to surrounding areas. However, the suburbanization that took place after 1970 was different from the suburbanization that had occurred earlier, after World War II. In this more recent wave of suburbanization, people moved beyond the nearby suburbs to farther-away towns. Sociologists have invented several new categories to describe these new types of suburban towns; two of the most notable are ex-urbs and edge cities.

The expression exurb (for “extra-urban”) refers to a ring of prosperous communities beyond a city’s suburbs. Often, these communities are commuter towns or bedroom communities. Commuter towns are primarily residential; most of the residents commute to jobs in the city. They are sometimes called bedroom communities because residents spend their days away in the cities and only come home to sleep. In general, commuter towns have little commercial or industrial activity of their own, though they may contain some retail centers to serve the daily needs of residents. Although most exurbs are commuter towns, most commuter towns are not exurban.

Exurbs vary in wealth and education level. In the United States, exurban areas typically have much higher college education levels than closer-in suburbs, though this is not necessarily the case in other countries. They typically have average incomes much higher than nearby rural counties, reflecting the urban wages of their residents. Although some exurbs are quite wealthy even compared to nearer suburbs or the city itself, others have higher poverty levels than suburbs nearer the city. This may happen especially where commuter towns form because workers in a region cannot afford to live where they work and must seek residency in another town with a lower cost of living. For example, during the “dot com” bubble of the late twentieth century, housing prices in California cities skyrocketed, spawning exurban growth in adjacent counties.

White Flight

Sociologists have posited many explanations for counterurbanization, but one of the most debated is whether suburbanization is driven by white flight. The term white flight was coined in the mid-twentieth century to describe suburbanization and the large-scale migration of whites of various European ancestries, from racially mixed urban regions to more racially homogeneous suburban regions. During the first half of the twentieth century, discriminatory housing policies often prevented blacks from moving to suburbs; banks and federal policy made it difficult for blacks to get the mortgages they needed to buy houses, and communities used restrictive housing covenants to exclude minorities.

White flight during this period contributed to urban decay, a process whereby a city, or part of a city, falls into disrepair and decrepitude. Symptoms of urban decay include depopulation, abandoned buildings, high unemployment, crime, and a desolate, inhospitable landscape. White flight contributed to the draining of cities’ tax bases when middle-class people left, exacerbating urban decay caused in part by the loss of industrial and manufacturing jobs as they moved into rural areas or overseas where labor was cheaper.

More recently, the concept has been extended to newer forms of suburbanization, including migration from urban to rural areas and to exurbs. In a similar vein, some demographers have described the rural rebound, and the newest waves of suburbanization, as a form of ethnic balkanization, in which different ethnic groups (not only whites) sort themselves into racially homogeneous communities. These phenomena, however, are not so clearly driven by the restrictive policies, laws, and practices that drove the white flight of the first half of the century.

A Suburban Neighborhood: Suburban neighborhoods often feature large, manicured lawns.

Models of Urban Growth

Models of urban growth try to balance the advantages and disadvantages of cities’ large sizes.

Learning Objectives

Summarize the various theories of urban growth and the implications each theory has for today’s society

Key Points

• The growth machine theory of urban growth says urban growth is driven by a coalition of interest groups who all benefit from continuous growth and expansion. Thus, the growth of cities is a social phenomenon.
• Urban sprawl results when cities grow uncontrolled, expanding into rural land and making walking, public transit, or bicycling impractical.
• Critics of urban life often focus on urban decay, which may be self-perpetuating, according to the broken windows theory.
• Urban renewal attempts to counter urban decay and restore growth.
• The New Urbanism and smart growth movements both challenge the value of urban growth and expansion, and they try to improve urban life by keeping it on a human scale.

Key Terms

• smart growth: Smart growth programs draw urban growth boundaries to keep urban development dense and compact.
• urban renewal: Urban renewal refers to programs of land redevelopment in areas of moderate- to high-density urban land use.
• New Urbanism: New Urbanism is an urban design movement that promotes walkable neighborhoods that contain a range of housing and job types.

Cities are dynamic places—they grow, shrink, and change. Sociologists have developed different theories for thinking about how urban populations change.

Growth Machine Theory

The growth machine theory of urban growth says urban growth is driven by a coalition of interest groups who all benefit from continuous growth and expansion. First articulated by Molotch in 1976, growth machine theory took the dominant convention of studying urban land use and turned it on its head.

The field of urban sociology had been dominated by the idea that cities were basically containers for human action, in which actors competed among themselves for the most strategic parcels of land, and the real estate market reflected the state of that competition. Growth machine theory reversed the course of urban theory by pointing out that land parcels were not empty fields awaiting human action, but were associated with specific interests—commercial, sentimental, and psychological. In other words, city residents were not simply competing for parcels of land; they were also trying to fulfill their particular interests and achieve specific goals. In particular, cities are shaped by the real estate interests of people whose properties gain value when cities grow. These actors make up what Molotch termed “the local growth machine. ”

Urban Sprawl

Whether explained by older theories of natural processes or by growth machine theory, the fact of urban growth is undeniable: throughout the twentieth century, cities have grown rapidly. In some cases, that growth has been poorly controlled, resulting in a phenomenon known as urban sprawl. Urban sprawl entails the growth of a city into low-density and auto-dependent rural land, high segregation of land use (e.g., retail sections placed far from residential areas, often in large shopping malls or retail complexes), and design features that encourage car dependency.

Urban sprawl’s segregated land use means that the places where people live, work, shop, and relax are far from one another, which usually makes walking, public transit, or bicycling impractical. As a result, residents must use an automobile. Urban sprawl tends to include low population density: single family homes on large lots instead of apartment buildings, single story or low-rise buildings instead of high-rises, extensive lawns and surface parking lots, and so on.

Critics of urban sprawl argue that it creates an inhospitable urban environment and that it encroaches on rural land, potentially driving up land prices and displacing farmers or other rural residents. Urban sprawl is also associated with negative environmental and public health effects, many of which are related to automobile dependence: increases in personal transportation costs, air pollution and reliance on fossil fuel, increases in traffic accidents, delays in emergency medical services response times, and decreases in land and water quantity and quality.

Urban Decay

Some have suggested that urban sprawl is driven by consumer preference; people prefer to live in lower density, quieter, more private communities that they perceive as safer and more relaxed than urban neighborhoods. Such preferences echo a common strain of criticism of urban life, which tends to focus on urban decay. According to these critics, urban decay is caused by the excessive density and crowding of cities, and it drives out residents, creating the conditions for urban sprawl.

BROKEN WINDOWS

An alternative theory suggests that density does not cause crime, and crime does not cause people to leave the city; when people leave, city neighborhoods are abandoned and neglected, resulting in crime and decay. This theory, known as the “broken windows theory,” argues that small indicators of neglect, such as broken windows and unkempt lawns, promote a feeling that an area is in a state of decay. Anticipating decay, people likewise fail to maintain their own properties.

RESPONSES TO DECAY

Cities have responded to urban decay and urban sprawl by launching urban renewal programs. Two specific types of urban renewal programs—New Urbanism and smart growth—attempt to make cities more pleasant and livable.

Smart growth programs draw urban growth boundaries to keep urban development dense and compact. In addition to increasing the density of cities, urban growth boundaries can protect the surrounding farmland and wild areas. Smart growth programs often incorporate transit-oriented development goals to encourage effective public transit systems and make bicyclers and pedestrians more comfortable.

New Urbanism is an urban design movement that promotes walkable neighborhoods with a range of housing options and job types. As an approach to urban planning, it encompasses principles such as traditional neighborhood design and transit-oriented development. A neighborhood designed along New Urbanist principles would have a discernible center (such as a square or a green) with a transit stop nearby. Most homes would be within a five-minute walk of the center and would provide a variety of housing options, including houses, row houses, and apartments to encourage the mixing of younger and older people, singles and families, and poor and wealthy.

Urban sprawl: Chicago, seen by air, shows urban sprawl

Broken windows: Broken windows in Detroit signal urban decay

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