Can the major problems of cities be solved?
Xiang Yan
A city, as described by Lewis Mumford, “is a geographic plexus, an economic organization, an institutional process, a theater of social action, and an esthetic symbol of collective unity. ” (Mumford, 1937) As such complex systems, cities are diverse from each other due to their distinct geographical, economic, political, social, cultural, and esthetic characteristics. Therefore, it is commonly accepted that every city is unique and problems ofeach city should be dealt with separately.In fact, many planners believe that each problem, even if they are of the same city or even the same place, is essentially unique as “for any two problems at least one distinguishing property could be found. ” (Rittel& Webber, 1973) Nevertheless, there are scientists, namely, Bettencourt and West, showing there are some simple mathematical laws about city growth and ambitiously proposing a unified theory of urban living.
1. Examining the“unified theory of urban living”
According to the researchof Bettencourt and West, the size of population is major determinant of most characteristics of a city (Bettencourt & West, 2010). Their work shows doubling the population of any city requires only an 85% increase in resources, and also, results in a 15% increase in all per capita socio-economic quantities. After a city doubles in size, however, negative metrics such as crime, traffic congestion and incidence ofcertain disease also increase by 15% (Bettencourt & West, 2010). These results, showing the similar patterns in West ‟s biological findings that mathematical equations could be devised to show the vital facts about animals—heart rate, size, caloric needs—
are interrelated (Lehrer, 2010), lead this former physics to confidently assert that the dynamics, growth and organization of cities could be simply understood through mathematical laws, and thus “a „grand unified theory of sustainability ‟ with cities and urbanization at its core could be developed.” (Bettencourt & West, 2010)
Nevertheless, is this really leading us to an unified urban growththeory, and can the cities be understood with these simple mathematical equations?Probably not. First of all, the generalization of the “15 percent law ”is still arguable. Richardson, in his book The Economics of Urban Size summarized the arguments relating to city size,and revealed that the costs and benefits of increasing the city size varied with the configuration of the city and its spatial relationship with other cities, and in particular with the economic structure of the city(Richardson, 1973). For example, rather than 15%, Segal (1976) found that “agglomeration effect” made units of labor and capital 8% more productive in the largest cities (Segal, 1976). That is to say, cities, with their respectively unique spatial patterns and economic structures, are most likely to follow diverse growth patterns, which as a result undermines the validity of a unified urban growth theory. However, it should be noted that most existing studies confirm that with the size of a city increaseit gains both the positive and negative effects of agglomeration, but the extents of which vary across studies (Richardson, 1973).
Regardless of the numeric exactness of the mathematical equations, another question is to what extent these scaling laws could help us “solve ” the cities. Is it as West asserts in biology that “[if] you tell me the size of a mammal, I can tell you at the 90 percent level everything about it in terms of its physiology, life history, etc. ” (West, 2011 )? Most planners would not agree with that. The first problem involves the effectiveness of
estimate (or prediction). Planning is “a process of preparing a set of decisions for action in the future,” (Dror, 1963) and thus planners aremaking predictions all the time, yet any experienced planner would confess no guarantee could be asserted to these predictions. It is not that planners are not confident with their work, but that future is never predictable as any change from factors involving economic, political, social, cultural, technological or environmental could make a difference. Thus, striving for accuracy, planners have developed the scenario planning approach to account for all the alternative possibilities.
A single value of urban variables estimated by the mathematical equations of West is therefore extremely vulnerable. So as any other estimate made by mathematical models, West limits his prediction at approximately 85 percent accuracy (Lehrer, 2010), which means in reality the estimate of variables is a range rather than a single value. Yet 85 percent accuracy may seem very high though, it is actually so rough that indicates few—if not no at all—implications. The reason is because cities normally involve millions of people, a slight deviation could mean a lot. For example, one percentage variance of GDP in a city with a population of one million could mean thousands of jobs difference. Another problem is that even assuming the estimate of urban variables is 100 percent accurate, these predicted metrics could offer few insights to understand cities and to solve their problems.Cities are gargantuan complex systems consist of various groups of individuals with diverse interests, values and norms, and in the absent of an overriding social ethic or social goodness their problems are desperately difficult to deal with. Rittel and Webber (1973) termed planning problems as “wicked ”problems due to their ill-defined and elusive nature in contrast to “tame ” ones scientists and engineers are facing. These wicked problems require painstaking efforts towards social issues such as
balancing efficiency and equity, hence estimating urban variables from some mathematical equations devoid of any social meaning barely constitutes a preliminary step.
2.The predictable and unpredictablenature of the cities
Although the above analysis disputes the notion that the nature and logic of cities could be readily understood through some mathematical equations, the discussion towards “a unified theory of urban living”provides us some insights to comprehend some predictable aspects of cities. As captured in West‟s scaling laws, just like some generic principles exists in biology, there are some universal patterns about cities. In general, all cities grow as a result of agglomeration effects: as the size of a city increase, it has higher resource usage efficiency, higher productivity, and more intense human interactions. At the same time, a city with a larger population unavoidably have to bear up with the diseconomies of agglomeration: worse traffic conditions, more crimes due to fiercer competition for resources and higher incidence of getting sick as diseases spread faster. The economics of diseconomies of agglomeration always come together, without exception for any city. As a result, the process of centralization and decentralization —usually termed as urbanization and suburbanization in the field of urban studies—alternatively happens in different periods of urban growthor sometimes simultaneously happens.
Notwithstanding, cities are as unpredictable as predicable. Just like any individual, one can tell as much about a city as one cannotregardless of how much he or she knows about the city before, as universal laws and distinctive characteristics coexist. A city is a combinationof unpredictable individuals who have their own thoughts, preferences and priorities, which renders an unpredictable nature to the city in that each unpredictable
movement of any individual could make a difference. The coexistence of conflicting values and interests among individuals also leads to some unsolvable problems of cities. No societal best state exists in any society yet rising pluralism appears everywhere, so some normative questions such as balancing efficiency with equity linger on in human societies.
3.The contribution and constrains of urban planning
The predictable nature of cities brings forth the tremendous accomplishments achieved by urban planningin contemporary cities. Paved streets, multifunctional buildings, beautiful parks, and sophisticated sewer lines are substantial evidence of how planners facilitate agglomeration economy in cities. Also, the existence of some universal laws among cities leads some cities to emulate the experiences of other successful cities. For instance, the industrial enterprise zone concept devised by Peter Hall primarily in UK cities has been adopted by countries worldwide to develop industry in disadvantaged areas.
However, the unpredictable nature of cities would make any planner who seeks to search for scientific bases —as for mathematical problems and chess puzzles —for planning problems feel frustrated. Planning problems are inherently “wicked ” problems, whereas science has developed to deal with “tame ” problems (Rittel& Webber, 1973). Dealing with problems in a pluralistic society, urban planning is destined to achieve no “optimal ” results, for in such a society “optimal ” could not even be defined. Also, urban planners should always keep in mind to avoid paternalism when handling planning problems, as their ideas could always be objectionable to some groups of people, which is already
evident by many criticism towards the Contemporary City idea devised by Le Corbusier and the Broadacre City idea devise by Frank Wright.
References:
Bettencourt, Luis, & West, Geoffrey. (2010). A unified theory of urban living. Nature, 467(7318), 912-913.
Dror, Yehezkel. (1963). The planning process: a facet design. International Review of Administrative Sciences, 29(1), 46-58.
Lehrer, Jonah. (2010, December 17). A physicist solves the city. The New York Times. Retrieved from http://www.nytimes.com/2010/12/19/magazine/19Urban_West-t.html?pagewanted=all
Mumford, Lewis. (1937). What is a city. Architectural record, 82, 59-62.
Richardson, Harry Ward, & Richardson, Harry W. (1973). The economics of urban size : Saxon House Lexington.
Rittel, Horst WJ, & Webber, Melvin M. (1973). Dilemmas in a general theory of planning. Policy sciences, 4(2), 155-169.
Segal, David. (1976). Are there returns to scale in city size? The Review of
Economics and Statistics, 58(3), 339-350.
West, Geoffrey. (2011, July). The surprising math of cities and corportations (Video File). Retrieved from
http://www.ted.com/talks/geoffrey_west_the_surprising_math_of_cities_and_corporations.html