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- Report n°1: summary
Summary of report n°1: the new constraints of urban development - March 2004
1) Between technological innovation and financial constraints: the new leeway for structuring urban development
Influence of the level of development on the urbanisation process
We have now crossed the threshold of 50% of the world population living in cities and it is forecast that two thirds of the population will live in cities by 2025.
In developed countries:
- a modest level of quantitative urban development: zero growth in the population flow to urban areas.
- an undergoing considerable qualitative development: . an increase in the number of square metres required by each temporary or permanent inhabitant or worker,
- obsolete infrastructure is undergoing renewal,
- increasing movements between population centres or within each population centre,
- a relative impoverishment of the centre.
In developing countries:
- a sharp drop in incomes in city centres resulting in inner city urban decay,
- a steep rise in city populations,
- there are 70 million new urban-dwellers each year,
- major disparities from one country to the next,
- the rapid urbanisation of developing countries is a transitory and non-exponential phenomenon.
Urban development, an opportunity to be seized?
In all countries, the same kind of curve can be observed: per capita income rises in line with the size of the city.
GDP of some of the world's largest cities in 2000, in billions of US dollars, and comparisons
| Tokyo | 1440 | France | 1429 |
|---|---|---|---|
| New York | 1050 | China | 1064 |
| Los Angeles | 620 | Brasil | 607 |
| Paris | 510 | India | 471 |
| Chicago | 400 | Australia | 394 |
| Osaka, San Francisco | 380 | Netherlands | 365 |
| Washington | 310 | Sub-saharian Africa | 313 |
| Boston | 260 | Russia | 250 |
| Hong-Kong | 180 | Turkey | 200 |
| Seoul, Toronto, Mexico | 150 | Indonesia | 150 |
| Sao Paulo | 110 | Greece | 112 |
| Singapore | 100 | Egypt | 100 |
| Bangkok, Istanbul | 60 | Pakistan | 65 |
| Shanghai | 50 | Peru | 54 |
| Cairo | 33 | Marocco | 36 |
| Manila | 25 | Vietnam | 26 |
| Jakarta | 16 | Tunisia | 20 |
dollar conversions performed as per World Bank recommendations.
This data represents the production of cities at market prices and therefore represents a certain level of purchasing power.
Governance and urban development
The advantages of cities are, however, merely potential and contingent on their proper administration. This effective administration is reflected in a quality environment, good public transport and control of urban sprawl.
The factors governing the productivity of cities:
The notion of the effective size of the employment market can be examined:
- from the worker's viewpoint,
- from the company's viewpoint.
Productivity is demonstrated by the effective size of the employment market with an elasticity of 2%. This signifies that by increasing the effective size of the employment market by 10%, productivity is increased by 2%.
Next, the effective size of the employment market is demonstrated by the total size of the employment market and therefore the size of the city, with an elasticity of 1%, then by the rapidity of access with an elasticity of 1.6% and finally inversely by the sprawl with an elasticity of -1.2%.
In conclusion, in a context of effective management, the urban phenomenon proves positive from an economic viewpoint since it leads to improved productivity and therefore higher incomes per inhabitant.
However, other constraints of an environmental and social nature can lead to a degradation in the quality of life in cities with repercussions on production capacities. Only effective governance makes it possible to avoid the traps inherent to all urban growth and turn the constraints generated by demographical change and/or the effects of uncontrolled urban sprawl into benefits.
2) The phenomenon of urban sprawl and city growth
Urban sprawl, which can be observed on all continents, is not a new phenomenon. With its varying forms, which depend on geographic, social and societal factors, this type of city growth displays some aspects that seem to be universal.
The terminology itself is diverse, underlining the complexity of the processes of peripheral growth in agglomerations, which makes it difficult to label this phenomenon precisely.
The development of cities around the world
On all continents, a relative decline in average urban growth rates has been observed for the last 20 or 30 years, compared to those of the preceding decades. This declining trend in demographic growth becomes more obvious if fixed perimeters are used, as a general process of spatial expansion is being seen everywhere. The extension of urban sprawl along communication routes often precedes the type of sprawl in which empty areas are filled.
Besides these general forms of urban sprawl, the patterns of peripheral expansion turn out to be extremely heterogeneous in terms of type of housing conditions, population pattern, means of protecting structures, construction type and social categories concerned. Despite geographical, socio-cultural and political situations differing greatly from one metropolitan area to the next, the processes of urban expansion are similar.
In metropolitan areas in developing countries:
- informal urbanisation of the outskirts is a classic working-class practice (e.g: clandestine housing developments, illegal occupation of sites),
- Periurbanisation may also result from planned development (e.g: satellite subcities in Delhi),
- A dispersal of affluent households across the outer peripheral area.
In large metropolitan areas in industrialised nations,
- the phenomena of remote and discontinuous urban extension linked to increased car use,
- home ownership.
Factors in periurbanisation
The reasons for urban sprawl are, of course, strongly influenced by the geographical and cultural situation of each agglomeration.
The role of transport and the sociological factors in urban sprawl
The phenomenon has been facilitated by:
- the development of modern transport,
- The growth of private car ownership.
The increased distance from urban centres and this dramatic rise in car ownership reflects ways of life in which there is a dissociation between areas for living, work and leisure, thus making individuals heavily mobile in a geographical sense.
The influence of single family housing
At a sociological level, it is interesting to examine the motivations of households in leaving city centres or moving slightly further out:
- people are always looking further away for less expensive property,
- a strong desire for property ownership,
- the scarcity of supply in densely populated districts and of collective housing,
- the role of accommodation as a social mirror,
- the favourable image of single-family houses within our societies,
- an increased demand for comfort.