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531.
This article estimates economies of scale for a sample of five cellular telephony firms in the United States. We reject constant returns to scale for all but the smallest firm studied; the remaining firms exhibit decreasing returns to scale. This finding suggests that scale economies cannot be used to justify the current regulated duopoly structure of United States cellular markets.  相似文献   
532.
The Cultural Economy of Cities   总被引:2,自引:0,他引:2  
An increasingly important fraction of contemporary economic activity is devoted to the production of cultural outputs, i.e. goods and services with high levels of aesthetic or semiotic content. This kind of economic activity is especially, and increasingly, associated with a number of large cities scattered over the globe. A conceptual account of this phenomenon is provided on the basis of an exploration of the character of place-specific forms of culture generation and the agglomerative tendencies of many kinds of cultural products industries. The empirical cases of Los Angeles and Paris are briefly discussed. The dynamics of production, distribution and location of major cultural products industries are also examined. The paper ends with a brief allusion to the modalities of spatial differentiation of culture in contemporary capitalism and to a prospective cultural politics.  相似文献   
533.
Current Issues in the Analysis of Commercial Real Estate   总被引:1,自引:0,他引:1  
This paper identifies and discusses a number of current issues regarding our understanding of commercial real estate markets. These issues include: 1) accurate estimation of the quantity and location of our nation's commercial space; 2) an understanding of the linkage between the space and capital markets for commercial real estate; 3) identification of the macroeconomic factors that affect the rate of return on commercial property and whether local market factors also affect the rate of return; 4) problems associated with measuring the return characteristics of equity investments in commercial property (including measures of the diversification benefits and inflation-hedging abilities of this asset class); 5) a better understanding of rental markets, including good measures of changes in effective rents over time; and 6) examination of the rationale for ownership of commercial space by corporate users. This paper reviews recent research related to these questions and suggests future research that should prove to be fruitful.  相似文献   
534.
Summary A sequential testing procedure called 2-SPRT for the meanμ of the negative binomial distribution with known exponentk is presented. For any fixedμ 0(μ 1<μ 0<μ 2), the 2-SPRT provides an asymptotic solution to the modified Kiefer-Weiss problem. Determination ofμ 0 such that the test provides an approximate solution to the Kiefer-Weiss problem is described. The behavior of the 2-SPRT and the Sequential Probability Ratio Test is investigated using Monte Carlo methods. The error probabilities and the average sample numbers are compared. All the computations were carried out on the Alabama Supercomputer.  相似文献   
535.
This paper focuses on the construction of forecasts over long horizons where a typical long-horizon forecast might span four years using 20 to 40 years’ data. It is argued that the presence of persistence in the form of unit or near-unit autoregressive roots poses substantial difficulties for long-horizon interval and point forecasting. These difficulties may not be overcome even by efficient pre-testing or model-selection procedures and might, in general, lead to point forecasts with large asymptotic root mean squared errors and undesirably wide prediction intervals.  相似文献   
536.
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538.
Dr. M. Riedel 《Metrika》1992,39(1):209-217
Summary In this note we characterize all linear transformations of random vectors which are invariant for a given parametric covariance family. Two one-dimensional covariance families are discussed in detail.  相似文献   
539.
A growing awareness of workplace hazards and identification of airborne contaminants, coupled with a changing safety and health regulatory environment, created an unexpected demand for new and innovative respirators in the early 1980s. 3M's Occupational Health and Environmental Safety Division broke new ground by taking the team concept further than ever before in the company. The division's Action Teams successfully designed, built and introduced products in less than half the time it would have taken previously. Robert Hershock, Charles Cowman and Douglas Peters describe how 3M learned important lessons about team selection, training, performance and motivation, the importance of project sponsors, and the role of middle management.  相似文献   
540.
To compensate for low civil service incomes, most lecturers at Indonesia's public universities hold one or more other jobs. The career path of the typical lecturer is away from teaching: the higher the classification the greater is the number of outside jobs and the smaller is the time devoted to undergraduate teaching. In effect, public universities cannot now compete for the time of their lecturers. Indonesia has been attempting to increase the quality of undergraduate education by investing in further education of lecturers. Our findings show that such efforts will be futile unless concomitant changes are also made on the demand side.  相似文献   
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