The following concepts and texts elaborating their meanings may help translators who are not familiar with them.

Spillover effects:
Cities and suburbs share a special interrelationship—they are both dependent on one another yet, simultaneously, in competition with one another. Because of their impact on the regional land and labor markets, fiscal policies undertaken in the central city can have effects that extend beyond its political jurisdiction. An understanding of these potential ***spillovers*** is critical in the design of regional economic policy. With no such understanding, one municipality's policies could lead to undesirable consequences for the metropolitan area as a whole, such as increasing suburban sprawl. http://www.springerlink.com/content/j8t20g514h521047/

Ripple effects:
As we enter into a new world of a global economy, we suddenly find that changes that begin with a ***ripple effect*** can ultimately lead to a tsunami outcome. The United States has recently experience a severe economic downturn resulting from a number of economic factors. As we inch closer and closer to becoming a global society, we see a shift in how we view the role of metropolitan and urban growth. Cities offer culture, entertainment and lucrative opportunities that are not as available in most rural communities. Over time, the attraction to cities from urban life has increased and in present day, the majority of people tend to be city dwellers. While each city takes on an identity as unique as its skyline, cities around the world also have certain traits and attractions common to each other. Geographies, commerce, race and gender have all played a key role in how cities have evolved and how they will continue to evolve in the future. In this new global economy, much of business is interacted via the internet between private parties. Companies like ebay, PayPal, Craigslist.com, Sykes.com etc. provide the means for international transactions to be available to even the most novice of international traders. The relatively low cost of developing a website and posting on the World Wide Web allows entrepreneurs to conduct business worldwide from any home computer or even a portable laptop with wireless internet capabilities. The Internet, with some exception, also allows anonymity. This anonymity significantly contributes to reducing the threat of racial or gender related issues from arising.
http://socyberty.com/economics/influences-and-impacts-of-a-g...

Spread effects:
An expression used by G. Myrdal (1975) to describe the filtering through of wealth from central, prosperous areas, to peripheral, less wealthy areas. Thus, increased economic activity at the core may stimulate a demand for more raw materials from the periphery, and technological advance in the core region may be applied to other regions. A belief in the spread effect lies behind the planning of growth poles; in a sense, the spread effect is the spatial equivalent of trickle-down economics.
http://www.answers.com/topic/spread-effect

Economies of scale// agglomeration economies:
The economic rationale for urbanization can be reduced to two basic concepts: the division of labour, and ***economies of scale.*** The former was introduced by Adam Smith and explains the benefits for productivity that arise from specialization between producers. It accounted for the great leap forward from craft production to factory production that gave rise to the industrial revolution. Economies of scale relate to the efficiencies that result from larger units of production. Larger firms can spread their fixed costs (rent, rates, R&D, etc.) over a larger volume of output and buy their inputs at lower prices. External economies of scale (or*** 'agglomeration economies'***) relate to the benefits that firms derive from locating near to their customers and suppliers in order to reduce transport costs. They also include proximity to a large labour pool, competitors within the same industry, and firms in other industries
http://www.informaworld.com/smpp/section~db=all~fulltext=713...



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Note added at 1 day1 hr (2010-06-30 08:36:45 GMT)
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URBAN FIELD
* The Urban field is the region economically and socially linked to a city.
* It is also referred to as
o Urban Regions:The commuter villages/communities dependent on large towns
o Functional Regions:The regions to/from which a city exports and imports.
o Hinterland:The area served by a seaport
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SPHERE OF INFLUENCE
The sphere of influence is the area of under influence of the Central Place.
A Central Place is a settlement which provides one or more services for the population living around it.

Simple basic services (e.g. grocery stores) are said to be of low order while specialized services (e.g. universities) are said to be of high order.

Having a high order service implies there are low order services around it, but not vice versa.

Settlements which provide low order services are said to be low order settlements.
Settlements that provide high order services are said to be high order settlements.


http://www.angelfire.com/ga2/ibgeography/urbanisation.html