涂装、包装、或分销业务。联同最初的成长，这些链接产业的发展有助于创建一个极限（临界值）足够大的活动来吸引辅助行业和活动（例如维护和修理、回收、安全、和商业服务）。
The existence of these interrelated activities establishes a pool of specialized labor with the kinds of skills and experience that make the area attractive to still more firms. Meanwhile, the linkages between all these firms help to promote interaction between professional and technical personnel, and allow for the area to support R & D (research and development) facilities, research institutes, and so on, thus increasing the likelihood of local inventions and innovations that might further stimulate local economic development.
存在这些相互关联的活动建立许多专业劳动与类型的技能和经验，使该地区吸引更多的公司。与此同时，这些公司之间的联系，有助于促进专业技术人员之间的互动，并允许该地区支持（研究与开发）设施、研究机构等，从而增加了当地的发展与创新的可能性，可能会进一步刺激当地经济发展。
Another part of the spiral of local economic growth is a result of the increase in population represented by the families of employees. Their presence creates a demand for housing, utilities, physical infrastructure, retailing, personal services, and so on—all of which generated additional jobs. This expansion, in turn, helps to create populations large enough to attract an even wider variety and more sophisticated kinds of services and amenities. Last—but by no means least—the overall growth in local employment creates a larger local tax base. The local government can then provide improved public utilities, roads, schools, health services, recreational amenities, and so on, all which serve to intensify agglomeration economies and so enhance the competitiveness of the area in being able to attract further rounds of investment.
另一部分的当地经济增长的螺旋是由于人口的增长为代表的家庭的员工。他们的出现创造了一个住房需求、公用事业、基础设施、零售、个人服务，所以在所有的额外的工作产生。这种扩张反过来有助于创建数量大到足以吸引一个更广泛和更复杂的类型的服务和设施。最后，但绝非至少在当地就业的整体增长创造了一个更大的地方税收。当地政府可以提供改善公共设施、道路、学校、医疗服务、休闲娱乐设施等，都为加强聚集经济，因此提高竞争力的区域能够吸引进一步轮投资。
2. 3 What is Planning Theory? 什么是规划理论
Planning theory is an elusive18 subject of study. It draws on a variety of disciplines and has no widely accepted canon.
规划理论的研究是一个难以琢摩的主题。它借鉴了多种学科，仍然没有普适标准。
We see the central question of planning theory as the following: What role can planning play in developing the city and region within the constraints of a capitalist political economy and a democratic political system? The emphasis is not on developing a model planning process but rather on finding an explanation for planning practice based on analyses of the respective political economies. Our effort is to determine the historical and contextual influences and strategic opportunities that shape the capacity of planners to affect the urban and regional environment.
我们看到规划理论的中心问题如下：规划在开发受资本政治经济和民主政治体系约束的城市中充当了什么样的角色。重点不在于开发一个模型规划过程，而在于找到一个解释说明规划实践是基于对各自的政治经济分析的基础上的。我们的工作是确定历史文本的影响和战略机遇，塑造规划师的能力来影响城市和地区的环境。
What is Planning Theory?什么是规划理论
It is not easy to define planning theory; the subject is slippery, and explanations are often frustratingly tautological or disappointingly pedestrian19. There are four principal reasons for this difficulty. First, many of the fundamental questions concerning planning belong to a much broader inquiry concerning the role of the state
in social and social transformation. Consequently, planning theory appears to overlap with theory, in all the social science disciplines, and it becomes hard to limit its scope or to stake out a turf（地盘、势力范围） specific to planning. Second, the boundary between planners and related professionals (such as real estate developers, architects, city council members) is not mutually exclusive（相互排斥的;互不相容的）; planners don?t just plan, and nonplanners also plan. Third, the field of planning is divided into those who define it according to its object (land-use patterns of the built and natural environments) and those who do so by its method (the process of decision making). Finally, many fields are defined by a specific set of methodologies. Yet planning commonly borrows the diverse methodologies from many different fields, and so its theoretical base cannot easily be drawn from its tools of analysis. Taken together, this considerable disagreement over the scope and function of planning and the problems of defining who is actually a planner obscure the delineation of an appropriate body of planning theory. Whereas most scholars can agree on what constitutes the economy and the polity and thus what is economic or political theory—they differ as to the content of planning theory.
不太容易定义规划理论：这门学科是棘手的，解释通常是令人沮丧的同义反复或者是令人失望的平庸无味。关于这个困难这有四个主要原因。第一，许多关于规划的基本问题属于一个更广泛的关于国家在社会和社会转型中角色的调查。因此，规划理论似乎与理论重叠，在所有的社会科学学科中，它变得很难限制其范围或者坚持地盘特定规划。第二，规划师和相关专业人员（比如房地产开发商，建筑师，市政府成员）的界限并不相互排斥；规划师不仅规划，非规划师也规划。第三，规划的领域被分为那些根据它的对象来定义（土地利用模式的建筑和自然环境）和那些根据它的方法（决策的过程）。最终，许多领域都有一组方法来定义，然而，规划通常借用了来自不同领域的不同方法论，因此它的理论基础不可
能简单的通过分析方法来提取。综上所述，在规划范围和功能上的相当大的分歧和定义谁实际上是一个规划师模糊界定一个规划理论的适当的主体问题？而大多数学者能就什么构成了经济和政体达成一致意见，因此什么是经济或政治理论——他们区别于规划理论的内容。
The amorphous20 quality of planning theory means that practitioners largely disregard it. In this respect planning resembles other academic disciplines. Most politicians do not bother with political theory; business-people generally do not familiarize themselves with econometrics; and many community organizers do not concern themselves with social theory. Planning as a practical field of endeavor, however, differs from other activities in its claim to be able to predict the consequences of its actions. Planners need to generalize from prior experience if they are to practice their craft. In their day-to-day work planners may rely more on intuition21 than explicit theory; yet this intuition may in fact be assimilated theory. In this light, theory represents cumulative professional knowledge. Though many practicing planners may look upon the planning theory of their graduate education as inert and irrelevant—and see in their professional work a kind of homespun, in-the-trenches pragmatism—theory allows one to see the conditions of this “pragmatism”. Just as Keynes22 warned of being an unwitting slave to the ideas of a defunct economist, we believe that it is also possible to be a slave to the ideas of a defunct planning theorist.
规划理论不成形的质量意味着从业者在很大程度上忽视它。在这方面规划类似其它学术科目。大多数政治家并不理会政治理论：商业人士一般不熟悉计量经济法；许多社区组织者并不关心社会理论。然而，规划作为一个实际努力的领域，它不同于其它活动能够声称可以预测其行为的后果。规划者如果要练习他们的工