Click here for Full Text

III. THE ROLE OF ECONOMIC ANALYSIS

Economists see the urban structure as:

Several core areas of study may be identified within the field of urban economics:

Economic Impact Studies

Economic impact studies examine: (a) dollar inputs entering a regional economic structure; (b) the process of dollars circulating throughout the system; and (c) the process of dollars leaving the system as regional output and the total wealth generated and its distribution.

Economic inputs create: (a) economic impacts (employment, taxes, etc.), (b) political impacts (public revenues, service demands, etc.), and (c) physical impacts (spatial expansion and contraction, social diseconomies, pollution, etc.).

Thompson discusses economic impact in terms of five stages of urban growth: [1]

Economic growth may hesitate and stagnate between any of these stages if the momentum at the end of a phase is not strong enough to carry the economy to the next stage.

Thompson introduces the concept of the "urban ratchet"--when the urban economy reaches a size in which certain functions are "locked-in", it will not slip backward.

Input-Output Analysis

Under input-output (IO) analysis, the economic structure of a community or region is defined and measured in terms of an inter-industry system or matrix.

Input-output analysis seeks to model the technological interrelationships of production and distribution in the economy through a system of simultaneous equations.

Each line of economic activity bears measurable relationships to every other economic activity in the region, which can be set forth in a series of equations--a huge revenue expenditure accounting system or transaction table. [2]

Widespread application of this approach has been hampered by the lack of adequate models and data deficiencies.

I/O analysis is relatively expensive and difficult to do and often is accepted as a precise and flawless tool--which it is not.

Income and Product Accounts

Income and product accounts involve a system of double-entry bookkeeping, established on the basis of asset changes without tracing interchanges in physical inventories.

Income and product accounts have been applied primarily in the study of the national economy.

The economy is seen as a mechanism for the production of goods and services for final disposi-tion as: (a) export sales, (b) private investment in industry and business, (c) govern-ment purchases, and (d) household consumption.

Total income is the sum of exogenous and endogenous income.

A regional multiplier (K) can be applied to determine the impact of shifts in either local economic activity or total income:

The multiplier may be modified in making projections if new lines of activity are introduced into a region or other events lead to changes in its relative competitive advantages.

Economic Base Studies

Cities survive by selling products or services to the "outside world," thereby gaining the wherewithal with which to pay for indispensable imports, i.e., goods and services not produced in the local economy [3]

Economic base studies divide the urban economy into two broad categories:

The underlying assumption is that expansion of basic activities usually results in growth of service activities and thus, growth in the total economy.

Andrews has suggested that a "purely" basic or nonbasic industry is a rarity--industries serve a mixture of export and local markets and may be more basic or more nonbasic but seldom exclusively so. [4]

Employment data of some firms must be apportioned between the basic and nonbasic sectors.

Andrews suggests that a distinction be made between those firms in which 80 to 100 percent of their sales is either export-oriented or locally oriented (high export or high local) and those in which 50 to 80 percent of their sales has such identifiable orientations.

Where the boundaries of the economic base area are drawn can influence the determination of what activities are basic and what activities are service or local-oriented.

Homer Hoyt observed that when employment is used as a measure, a ratio occurs between basic and nonbasic activities. Empirical studies have shown that this ratio varies over a relatively narrow range of from 1 to 0.5 to 1 to 2 (with the base activity computed as the constant).

These multipliers have been used in making population projections, as well as projections of employment and economic activities (assuming a constant or predictably changing ratio).

Employment data are also used to calculate location quotients, sometimes called coefficients of localization or specialization.

Solving the following equation for X determines the number of workers that would be employed in industry i if the community produced just enough of that industry's product to supply its own needs. [6]

If actual employment is in excess of X, then industry i may be assumed to be export oriented; if actual employment is below X, then products of this industry are assumed to be imported.

Economic base multipliers and location quotients can be generated for various units of measurement, including: (1) employment data, (2) payrolls, (3) value added, (4) value of production, (5) physical production, and (6) dollar income and expenditure accounts. [7]

Output per worker (productivity) may increase without parallel increases in employment; rise in productivity may be associated with an increase in the rate and total wage assigned to individual jobs.

Payrolls data are open to significant price change adjustments but may provide a clue to a community's standard of living if these data can be obtained in terms of annual distributions.

Physical production, value added, and value of production do not apply to all sectors and therefore have limited application. Value added and value of production may be clouded by complex price movements and may encounter problems with intangible inputs and value products.

Dollar income and expenditures accounts, in combination with employment data, provide the most comprehensive measure of economic activity. The complexity and difficulty of tracing monetary transactions, coupled with data problems, limit the application of these measures.

Much of the appeal of economic base studies stems from their simplistic application, which can also lead to fallacious and contradictory results.

Applicability of the economic base approach tends to decrease with increasing size of the urban center and tends to increase with increasing specialization and division of labor between centers. [9]

Large, highly diverse metropolitan centers survive and grow because highly developed and diverse business and consumer services enable such centers to attract new basic industries to offset those that may decline.

Economic Dominants Analysis

Economic dominants may be export or local in their market orientation and, as industry groups, claim an arbitrary minimum proportion of total area employment--3%, 4% or 5% depending on the local economic structure (and cost constraints of conducting the study).

This approach based on the hypothesis that the quantitative and qualitative character of the total urban economy can be understood through a continuing study of those industries or economic activity groups that dominate the area in terms of employment and other strategic factors. [10]

Selected economic dominants (industry groups) are subjected to:

Across-the-board integration of selected industry group data is accomplished by means of: (1) formal analytical identification of primary linkage relationships among export and ancillary (local) dominants industry groups at the local level; and (2) summation of the individual dominants on an employment basis for the current year.

Subdominant industry groups also may be identified--industry groups whose employment shares are just below the minimum level of dominants but still of significant size--because they represent an underlying "seedbed" of established economic activity. [11]

Summary

The urban economy has been studied primarily in terms of three conceptual systems--input-output analysis, income product accounts analysis, and economic base studies.

As data sources become more extensive and more refined, and as the data handling capacity of computers receives wider utilization, it is likely that the "rough edges" of these three models will be smoothed away so that they nearly fit as a single system of analysis. When this is accomplished, the integration of broader theoretical concerns of economics will be possible.

Endnotes

[1] Wilbur Thompson, A Preface to Urban Economics (Washington, D.C.: Resources for the Future, 1963).

[2] Wassily W. Leontief, The Structure of the American Economy, 1919-1939 (Oxford: Oxford University Press, 1951), p. 11.

[3] Thompson, op. cit., chapter 1.

[4] Richard D. Andrews, "Mechanics of the Urban Economic Base," Land Economics (November 1953), pp. 344-49; "Urban Economics: An Appraisal of Progress," Land Economics (August 1961), pp. 223-225; "Economic Planning for Small Areas: An Analytical System," Land Economics (May 1963), pp. 145-155; "Economic Planning for Small Areas: The Planning Process," Land Economics (August 1963), pp. 253-264.

[5] William J. Reilly, The Law of Retail Gravitation (New York: G.P. Putnam Sons, 1931)

[6] Charles M. Tiebout, The Community Economic Base Study (New York: Committee for Economic Development, 1962), p. 47.

[7] Andrews, "Economic Planning for Small Areas: The Planning Process," Land Economics (August 1963), pp. 253-264.

[8] Ralph W. Pfouts, "An Empirical Testing of the Economic Base Theory," Journal of the American Institute of Planners (Spring 1957).

[9] Hans Blumenfeld, "The Economic Base of the Metropolis," Journal of the American Institute of Planners (Fall 1955).

[10] Andrews, "Economic Planning for Small Areas: An Analytical System," Land Economics (May 1963), pp. 143-155.

[11] Ibid., p. 151.