By Tito Alegria

The population situated along the United States-Mexico border is concentrated in cities which form bi-national adjacencies. On this geographical border, those adjacent cities are frequently thought of as "twin cities" or as a "bi-national metropolis." They have even introduced the term "trans-border metropolis" to describe the continuous bi-national urbanism formed by the neighboring cities of each country, including San Diego and Tijuana. This continuous trans-border urbanism is considered a single urban unit whose integration is rooted in the relations and interactions between each pair of adjacent cities. This idea of the "trans-border metropolis" is naturally inclined to be impressionistic; it contains a theoretical fallacy that is null of any substantial indicators.

In theoretical terms, this impressionistic perspective confuses the terms interaction with integration, and region with economic space. If there are a large number of excursions between San Diego and Tijuana, they are due mainly to the structural digression between the two countries in which they are located. This interaction stimulates local markets in both cities, but it does not convert them into trans-border markets. The economic activity produced by certain goods and services from Tijuana and San Diego are considered trans-border, but these do not integrate the two neighboring cities into one bi-national urban region. If this interaction were to conjugate the place of origin and the destination of a good into one single region, then the cities of Chiapas and Las Vegas­which "share" the same economic space in the coffee industry­could also be an example of trans-border urbanism, and thus lead to a conceptual disparity.

This essay will focus on debating why the municipalities located in the northern Mexican border do not form a metropolis with their neighboring cities situated in the United States.

1. A trans-border urban region is non-existent. In general terms, the components of an urban region are integrated and have a common goal. First, in the absence of natural obstacles, the spatiality of a regional urban system is only limited by the cost of the distance. Second, the goods and services of higher rank are produced in certain central areas of the region, but are not consumed by the inhabitants in all the locations of the district. Third, the social structuralization is rooted regionally and nationally. The behaviors of the agents in a region are materialized as a social structuralization (i.e. social classes) unique to each area. The interest which exists to interact and the mutual recognition of the social stratification of these agents in the structure as a whole is the foundation of a society. All these factors acquire the same structural significance only when they are interacting within it. These three determinants do not work in a trans-border context. First, even though there exist minimal limitations when it comes to transportation costs (the time in crossing the international border), the main constraints facing the formation of a trans-border region are the international limitations. For example, only 50% of Tijuana's inhabitants can legally cross the border. All those who reside in San Diego can legally cross, but very few do so because of fear or lack of interest. Second, a large part of the local functions only address national consumers such as government, health and education in the public sector and professional services found in the private sector, the result of international restrictions. Third, the social ramification process cannot be bi-national, and because of this the social structure that sustains the integration of a region also cannot materialize itself through a border. The practice of agents and social classes is disconnected on both sides of the international line. In addition, both sides of the border have contrasting ways to guarantee the reproduction of their social structures due to the different regulations of their respective states and nations, and this cannot be bi-nationally exempt from situations of colonialism.

2. There exist no trans-border markets that are mutually integrated.

In a metropolis­a territory that is systematically integrated­a good or service encompasses only one market. In case there was to be two markets for one good, one neighboring the other, then we find ourselves in the presence of two urban regions. In general terms, these goods and services only participate in a single market; first because it has one single price and second because supply and demand modify the level of activity. These conditions do not apply, however, in a trans-border zone. This is caused by the structural differences between Mexico and the United States. A single good or service participates in two systems of relative pricing, one in Tijuana and the other in San Diego. This price difference is reflected in the salaries which workers are compensated. For example, in 1998 the cost of labor in the manufacturing sector in San Diego was $12.20 per hour and $1.90 in Tijuana. Another case where this is exemplified is dental services; a tooth fixing which is priced at $120 in San Diego and $30 in Tijuana. Second, trans-border supply and demand has no impact over levels of activity. The markets pertaining to the same good or service act in an isolated manner and the level of mutual dependency is minimal, even in those markets where there is a relative higher interaction. For example, in the labor market the demand for workers in San Diego does not modify the quantity of trans-migrant employees in Tijuana. The number of these workers depends predominantly on the salary differences between these cities.

3. Disparities in structuralism and urban dynamics Since this geographical border separates cities that belong to countries with different economies, their structural organization of the use of land and their urban dynamics respond to different factors. Due to this, the urban form of a metropolis on one side of the border is different to that found in its adjacent city. When it comes to the use of land, a major part of the blue collar jobs in Mexican cities are distributed in central and sub-central areas where a high density in employment exists. The most important city centers are established in areas where residents with higher gross income are situated. In the United States, these jobs are distributed in large amounts in sub-centers all throughout a city where a low level of employment usually exists. On the other hand, residents of Mexico usually locate themselves in areas with greater urban densities and those with higher earnings reside in centrally located zones. These differences in urban configuration are due (on the supply side) to the dependency that Mexico's economic activity has on economic scale; they possess a technological dualism and less productivity and sales by the consumer. For example, in Tijuana the diminutive levels of consumerism per capita caused by low salaries makes the supply side acquire greater market areas for each good and service. This can only occur if products expand from certain points of sale inside the urban space. In this context, consumers have higher costs in transportation commuting from their homes. To compensate for these expenses and attract consumers, suppliers minimize the price for which a good is sold, but this causes an increase in the economic scale. Several economies that take advantage of economic scales are technically complementary; these tend to situate themselves in the same zone, generating an agglomeration of external economies and engendering the emergence of centers. In cities in the United States, the concentration of city centers due to the economies of scale occur less frequently because there is a sufficient amount of consumerism dispersed all around the city.

On the demand side, the cost and time in transportation are factors that influence where a person can reside. In Mexico, those with greater incomes can choose to live in cities. Those who receive less income do not have a choice and are forced to locate themselves in shanty housing or acquire a house with public finance. This type of housing is generally located in the peripheral zones of a city. Since salaries are lower in Mexico, the portion of money spent in transportation is greater. In Tijuana for example, the cost of public transportation in an urban setting is three times greater than in San Diego relative to salary. This causes families in Tijuana to settle in larger concentrated areas, producing spaces that are more compressed in comparison to those found in San Diego. In the year 2000, the urbanized area of Tijuana had a density of 52 residents per acre compared to 11 residents per acre in San Diego. The transformation that has taken place in the urban sector also varies on both sides of the border. Geographically, cities in the Mexican border have specialized themselves in the manufacturing and exporting sectors. In the United States, major urban areas concentrate service and government sectors. If a TLCAN [NAFTA] effect were to arise, it would most likely be a minimal one that would follow the previous tendencies, suggesting a growth in the manufacturing sector in Mexico, while affecting economic proliferation in the United States. These demographic contrasts are senile. Since 1930 the percentage in population growth of Tijuana has been greater compared to San Diego, and in the last 40 years the sense in growth has been contrasting between these two cities. While Tijuana keeps on growing due to the large amount of migrants moving there from all over the country, its national economy keeps declining and becomes more unaligned to the U.S. economy, especially in the gross domestic product. In contrast, San Diego receives national and regional stimulus. Its change in demography is directly impacted by its country and state economical cycle.

4. Differentiating problems and praxis in planning Due to the asymmetries that are present in Mexico and the United States, urban problems tend to contrast in these two countries. Cities on the United States border experience, for the most part, complete urbanization. In contrast, all the bordering Mexican cities have a deficit in public services and in almost every type of infrastructure. The urban problems that need to be addressed are different in each country, with the exclusion of those ecological issues that are equally shared such as water and air pollution. Trans-border urban planning is non-existent. There is no bi-national institution that unifies both local governments, and no legislation that would permit this action, and thus no inclination to take on bi-national planning. Two obstacles prevail: one is that the problems that need to be resolved are at odds between both sides of the border (with the exception of environmental issues that are administered on the federal level). The second issue deals with the incompatibility that exists in the practice of planning. In Mexico, planning is not executed in a contiguous manner; priority is given to client relationships formed in the public sector. On the U.S side, planning is divorced from the technical sphere and the elaboration of economic plans. The few attempts that exist to confront existing problems that have a bi-national impact­such as the development of an international airport Tijuana-San Diego­have been unsuccessful as a result of one of the most significant of these structural reasons. In Mexico, bi-national relations are a federal concern and in San Diego they are local.

Tito Alegria teaches at the Colegio de la Frontera Norte, Tijuana.
Printed with permission of Tito Alegria.