City

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A city is an urban area with a high population density and a particular administrative, legal, or historical status.

Large industrialized cities generally have advanced systems for sanitation, utilities, land usage, housing, and transportation and more. This close proximity greatly facilitates interaction between people and firms, benefiting both parties in the process. However, there is debate now whether the age of technology and instantaneous communication with the use of the Internet are making cities obsolete.[1][2]

A big city, or metropolis, may have suburbs. Such cities are usually associated with metropolitan areas and urban sprawl, creating large numbers of business commuters. Once a city sprawls far enough to reach another city, this region can be deemed a conurbation or megalopolis.

The birth of cities

There is insufficient evidence to assert what conditions in world history spawned the first cities. Theorists, however, have offered arguments for what the right conditions might have been and have identified some basic mechanisms that might have been the important driving forces.

Cities or agriculture first?

The conventional view holds that cities first formed after the Neolithic revolution. The Neolithic revolution brought agriculture, which made denser human populations possible, thereby supporting city development . The advent of farming encouraged hunter-gatherers to abandon nomadic lifestyles and to choose to settle near others who lived off of agricultural production. The increased population density encouraged by farming and the increased output of food per unit of land, created conditions that seem more suitable for city-like activities. In his book, “Cities and Economic Development,” Paul Bairoch takes up this position as he provides a seemingly straightforward argument, which makes agricultural activity appear necessary before true cities can form.

According to Vere Gordon Childe, for a settlement to qualify as a city, it must have enough surplus of raw materials to support trade . Bairoch points out that, due to sparse population densities that would have persisted in pre-Neolithic, hunter-gatherer societies, the amount of land that would be required to produce enough food for subsistence and trade for a large population would make it impossible to control the flow of trade. To illustrate this point, Bairoch offers “Western Europe during the pre-Neolithic, [where] the density must have been less than 0.1 person per square kilometer”, as an example. Using this population density as a base for calculation, and allotting 10% of food towards surplus for trade and assuming that there is no farming taking place among the city dwellers, he calculates that “in order to maintain a city with a population of 1,000, and without taking the cost of transportation into account, an area of 100,000 square kilometers would have been required. When the cost of transportation is taken into account, the figure rises to 200,000 square kilometers..." . Bairoch noted that 200,000 square kilometers is roughly the size of Great Britain.

In her book “The Economy of Cities,” Jane Jacobs makes the controversial claim that city-formation preceded the birth of agriculture. Jacobs does not lend her theory to any strict definition of a city, but her account suggestively contrasts what could only be thought of as primitive city-like activity to the activity occurring in neighboring hunter-gatherer settlements.

To argue that cities came first, Jacobs offers a fictitious scenario where a valued natural resource leads to primitive economic activity that eventually creates conditions for the discovery of grain culture. Jacobs calls the imaginary city New Obsidian, where a stock of obsidian is controlled and traded with neighboring hunting groups. Those that do not control the stock demand the obsidian, so hunters travel great distances to barter what they have. Hunters value obsidian because “[o]bsidian makes the sharpest tools to be had" . Hunters arrive with live animals and produce, providing New Obsidian with food imports. When New Obsidians want goods that they do not have access to at their settlement, they take the obsidian as a currency to other settlements for trade. This basic economic activity turns the little city into a sort of “depot” where, in addition to exporting obsidian, a service of obtaining, handling and trading of goods that are brought in from elsewhere are made available for secondary customers. This activity brings more people to the center as jobs are created and goods are being traded. Among the goods traded are seeds of all different sorts and they are stored in unprecedented combinations. In various ways, some accidental, the seeds are sown, and the variation in yields among the different types of seeds are readily observed, more readily than they would in the wild. The seeds that yield the most grain are noticed and trading them begins to occur within the city. Owing to this local dealing, New Obsidians find that their grain yields are the best and for the first time “the selection becomes deliberate and conscious. The choices made now are purposeful, and they are made among various strains of already cultivated crosses, and their crosses, mutants and hybrids . The new way of producing food allows for food surplus and the surplus is offset by the population increase that results from an increase in labor that the new production method has created. The new source of food allows New Obsidian to switch its imports from mostly food, to mostly other materials that neighboring settlements are rich in, but could not barter with before. The craftsman that develop in New Obsidian make good use of the explosion of the new material imports and the work to be done increases rapidly along with the population as neighboring settlements are absorbed by the city activities.

Why do cities form?

Theorists have suggested many possible reasons for why people would have originally decided to come together to form dense populations. In his book “City Economics,” Brendan O’Flaherty asserts “Cities could persist—as they have for thousands of years—only if their advantages offset the disadvantages" . O’Flaherty illustrates two similar attracting advantages known as increasing returns to scale and economies of scale, which are concepts normally associated with firms, but their applications are seen in more basic economic systems as well. Increasing returns to scale occurs when “doubling all inputs more than doubles the output [and] an activity has economies of scale if doubling output less than doubles cost” . To offer an example of these concepts, O’Flaherty makes use of “one of the oldest reasons why cities were built: military protection” . In this example, the inputs are anything that would be used for protection (i.e.: a wall) and the output is the area protected and everything of value contained in it. O’Flaherty then asks that we suppose that the area to be protected is square and each hectare inside it has the same value of protection. The advantage is expressed as: .

(1) O = s², where O is the output (area protected) and s stands for the length of a side. This equation shows that output is proportional to the square of the length of a side.

The inputs depend on the length of the perimeter:

(2) I = 4s, where I stands for the quantity of inputs. This equation shows that the perimeter is proportional to the length of a side.

So there are increasing returns to scale:

(3) O = I² / 16. This equation (algebraically, combining (1) and (2)) shows that with twice the inputs, you produce quadruple the output.

Also, economies of scale:

(4) I = 4O^{1 / 2}. This equation (combining (1) and (2)) shows that the same output requires less input.

“Cities, then, economize on protection, and so protection against marauding barbarian armies is one reason why people have come together to live in cities...” .

Similarly, “Are Cities Dying?” by Edward L. Glaeser, delves into similar reasons for city formation: reduced transport costs for goods, people, and ideas. An interesting piece from Glaeser’s article is his argument about the benefits of proximity. He claims that if you double a city size, workers have a ten percent increase in earnings. Glaeser furthers his argument by logically stating that bigger cities don’t pay more for equal productivity in a smaller city, so it is reasonable then to assume that workers actually become more productive if you move them to a city twice the size than they initially worked in. However, the workers don’t really benefit from the ten percent wage increase because it is recycled back into the higher cost of living in a bigger city.

Geography

Modern city planning has seen many different schemes for how a city should look. The most commonly seen pattern is the grid, favoured by the Romans, almost a rule in parts of the Americas, and used for thousands of years in China. Derry was the first ever planned city in Ireland, begun in 1613, with the walls being completed five years later. The central diamond within a walled city with four gates was thought to be a good design for defence. The grid pattern chosen was widely copied in the colonies of British North America. However, the grid has been around for far longer than the British Empire. The Ancient Greeks often gave their colonies around the Mediterranean a grid plan. One of the best examples is the city of Priene. This city even had its different districts, much like modern city planning today. Fifteen centuries earlier the Indus Valley Civilization was using grids in such cities as Mohenjo-Daro. Grid plans were popular among planners in the 19th century; such plans were typical in the American West, in places such as Salt Lake City and San Francisco. Also in Medieval times we see a preference for linear planning. Good examples are the cities established in the south of France by various rulers and city expansions in old Dutch and Flemish cities.

Other forms may include a radial structure in which main roads converge on a central point, often the effect of successive growth over long time with concentric traces of town walls and citadels - recently supplemented by ring-roads that take traffic around the edge of a town. Many Dutch cities are structured this way: a central square surrounded by concentric canals. Every city expansion would imply a new circle (canals + town walls). In cities like Amsterdam and Haarlem, and elsewhere, such as in Moscow, this pattern is still clearly visible.

History

Further information: Historical cities and List of largest cities throughout history

Towns and cities have a long history, although opinions vary on whether any particular ancient settlement can be considered to be a city. A city formed as central places of trade for the benefit of the members living in close proximity to others facilitates interaction of all kinds. These interactions generate both positive and negative externalities between other’s actions. Benefits include reduced transport costs, exchange of ideas, sharing of natural resources, large local markets, and later in their development, amenities such as running water and sewage disposal. Possible costs would include higher rate of crime, higher mortality rates, higher cost of living, worse pollution, traffic and high commuting times. Cities will grow when the benefits of proximity between people and firms are higher than the cost. The first true towns are sometimes considered to be large settlements where the inhabitants were no longer simply farmers of the surrounding area, but began to take on specialized occupations, and where trade, food storage and power was centralized. In 1950 Gordon Childe attempted to define a historic city with 10 general metrics[3]. These are: