关于规模经济与规模报酬

关于规模经济与规模报酬 关于“规模经济”与“规模报酬” Dictionary of Economics and business Economy of scale: The reduction in average unit cost associated with the increase in the size of plant or activity up to a point and thereafter an increase in such cost. //p.157 External economies and diseconomies: External economies are increases in efficiency within the producing unit, not paid for by the unit but resulting from action outside the unit. The unit may be a firm or an industry. E.g., the entry of a firm into an industry may lower the costs of all firms previously in the industry. This economy is external to the firm but internal to the industry. If a loss in efficiency were involved, the decrease would be termed a “diseconomy”. //p.178 Internal economies and diseconomies: Internal economies are increases in efficiency within the producing unit through better organization or differences in the scale of operations. Care must be taken to distinguish the unit used, e.g., economies that are external to the firm may be internal to the industry. Economies that are increases in efficiency but outside the unit referred to are called external. An example of an economy external to the firm but internal to the industry: industry-wide advertising to which a number of firms contribute. Diseconomies are decreases in efficiency similarly classified. //p.249 Returns to scale: Comparing the returns of an enterprise (if all factors of production are proportionately increased or decreased) to the scale of operations. Cf. constant cost, increasing cost, decreasing cost. Distinguish diminishing marginal productivity, law of, which is concerned with varying the proportions of the factors. Decreasing cost: The situation in which average total unit cost of a business decreases over the usual range of output as the volume of business increases. True of railroads and other transport agencies. //p.128 Constant cost: The situation in which average cost per unit of output remains unchanged as output varies. //p.101 Constant cost industry: An industry where average total unit cost remains the same as production volume increases or decreases. //p.101 Increasing cost: The situation in which average total unit costs of a business increase as the volume of business increases. True over large ranges of output for farming, mining, fishing, and lumbering, the so-called extractive industries. //p.233 Increasing cost industry: An industry whose average total unit cost increases as production volume increases over a given range of production. //p.233 Increasing returns to scale: The situation in which a proportionate increase in each factor of production results in a more than proportionate increase in output. //p.234 Decreasing returns to scale: The situation in which a proportionate increase in each factor of production results in a less than proportionate increase in output. //p.128 ----Dictionary of Economics and business The Macmillan Dictionary of Modern Economics Economies of scale: Reductions in the average cost of a product in the long run, resulting from an expanded level of output. Also known as long run increasing returns. //p.125 Returns to scale: The rate at which output changes as the quantities of all inputs are varied. If , for example, inputs are multiplied by a factor of 2 and output goes up by the same multiple, constant returns to scale exist. If output goes up by less than a factor of 2 decreasing returns to scale prevail, and if by more than a factor of 2 increasing returns to scale prevail. The term “scale” is useful in reminding us that all inputs are being varied. This should be carefully distinguished from the situation in which only one input is varied in which case the law of diminishing returns will eventually come into play. There are however no such “laws” about the behaviour of returns to scale. It is an empirical issue as to whether they are constant, increasing or decreasing. The diagram below shows iso-product curve and illustrates all three types of returns to scale. Section ab illustrates increasing returns, bc, constant returns and cd decreasing returns. //p.377 ------The Macmillan Dictionary of Modern Economics A Dictionary of Economics and Commerce Economies of scale: Throughout the past two hundred years there has been a tendency for the scale of production to increase, one of the main features of industrial development during this period being the increasing size of the business unit in most lines of production. The reason for this development has been mainly to take advantage of some of the economies associated with large-scale production, although in more recent times there has often been the additional motive of attempting to obtain a larger share of the market for a commodity and thereby some degree of monopoly power. Economies of scale may be of two kinds-----internal and external. Internal economies are those which any single firm by its own organization and effort can enjoy, external economies being open only to a whole industry. External economies are associated with localization of industry. Some of the principal internal economies of scale are as follows: (i) economies in the use of factors of production, since to expand output by a given amount does not require a proportionate increase in the quantities of the factors of production employed. To double output twice the amount of land will not be required, nor is it likely to be necessary to double the labour force. Greater division of labour and specialisation will be possible, and more specialised capital can be employed as can units of capital too large for a small firm to make effective use of; (ii) there will also be economies in administration, since it is unlikely that to double its output a firm will require to double its office staff. The large firm too can make use of office machinery, only extremely large firms having sufficient work to make it worthwhile to employ the latest electronic computers; (iii) marketing economies are possible----both in the form of lower prices for buying raw materials in bulk and in the selling costs of the firm; (iv) on the financial side it is often cheaper for a large firm to borrow, whether from the bank or by an issue of debentures, than for the small firm; (v) only the large firm can undertake research work on its own account. //p.148-49 Returns to scale (--Laws of returns): There are two sets of laws of returns: (i) Increasing and diminishing returns resulting from variations in the proportions in which the factors of production are combined; (ii) Increasing and diminishing returns resulting from a change in the scale of production (“pure” returns to scale). If one or more factors remain fixed and increasing amounts of the other factor or factors are combined with the fixed factors, increasing returns will occur until the optimum proportion has been reached after which diminishing returns will set in. This is applicable to any form of production. Since it is often necessary to employ large, indivisible units of capital it is not always possible to combine factors in the optimum proportion. Assuming, however, the optimum proportion to have been reached, the scale of production may be accompanied by increasing returns to scale, though few economies of scale appear to be entirely independent of variation of the proportions in which factors are combined. //p.399 ----- A Dictionary of Economics and Commerce Encyclopedia of Economics (ed. by Douglas Greenwald) Economies of scale: Given the state of technology in an industry, a systematic relationship will exist between the size or scale of plants and firms operating in that industry and the lowest attainable level of the average cost of production and distribution. With size or scale measured in terms of the designed rate of output of the production facilities employed by the plant or firm, increases in the scale of production normally make possible reductions in average cost, at least to a certain size called the minimum optimal scale. The reduction in average cost made possible by increasing size are called economies of scale. //p.327 Real and Pecuniary Economies In the normative evaluation of economies of scale, an important distinction must be made between real and pecuniary economies. Real economies of scale are cost reductions which reflect genuine improvements in efficiency: fewer input are required to produce any given volume of output. Society clearly benefits since scarce resources are used more productively. Pecuniary economies of scale are cost reductions which simply reflect the ability of the larger firm to obtain inputs at lower prices through the exercise of monopsony power. The firm reaps a private benefit at the expense of its resource suppliers, but no improvement in the ratio of physical input to physical output, and hence no social benefit, is implied. For the most part, economies of large-scale plants, which are based on production technologies, are real. To the extent that they exist, some economies of multiplant operations are likely to be purely pecuniary in nature. //p.328 Another elaboration is that the law of diminishing returns may, under certain circumstance, be temporarily replaced by its logical opposite, the law of increasing returns (better known as economies of scale). If the input that is, relatively speaking, scarcest in the production of a certain item can be augmented, output may well rise disproportionately. For example, a large, fully equipped factory may have had to operate inefficiently because of a shortage of workers who could handle the machinery. Breaking this bottlenek, e.g., through immigration or by training more workers, will permit better use of the resources (land and machinery) that are already available, so that the productivity per worker might well increase. But this effect will work only up to a point. When one or another of the inputs becomes relatively scarce, the law of diminishing returns will again come into play. //p.244 ----- Encyclopedia of Economics (ed. by Douglas Greenwald) Economics — Principles and policy ( by William J. Baumol, Alan S. Blinder) Economies of scale: Roughly, it means that when the firm expands all of its outputs, its cost per unit of output will go down. This is not true of every type of industry, but it seems to characterize many of them, at least up to some level of production. Automation, assembly lines, sophisticated machinery and equipment are all believed to help many large firms reduce their production cost. //p.394 …… if the producer gets diminishing returns from his inputs as he uses more of them, does this not prevent him from obtaining scale economies? The answer is that it does not, for they deal with two fundamentally different issues: 1. How much can output expand if we increase the quantity of just one input by some specified amount, holding all other input quantities unchanged? 2. How much can output expand if all inputs are increased simultaneously by the same percentage? The law of diminishing returns provides an answer to the first of these questions, while economies of scale are pertinent to the second question. (Note the analogy to a scale model, in which all components are changed in size proportionately.) //p.401 ---- Economics —— Principles and policy ( by William J. Baumol, Alan S. Blinder) 克鲁格曼:《国际经济学》 我们通过假定生产得越多则每单位产品的劳动投入越少来描述规模经济;但 是，我们并没有这种生产力的提高源自何处——是由于现有厂商生产规模的 扩张，还是行业中厂商数目的增加呢,因此，为了分析规模经济对市场结构的影 响，我们必须清楚那种生产的增加对削减成本是必要的。规模经济可分为外部的 和内部的。外部规模经济指的是单位产品成本取决于行业规模而非单个厂商的规 模;内部规模经济则指的是单位产品成本取决于单个厂商的规模而不是其所在的 行业规模。 外部的和内部的规模经济对市场结构具有不同的影响。一个只存在外部规模 经济的行业(即大厂商没有优势)一般由许多相对较小的厂商构成，且处于完全 竞争的状态;相反，存在内部规模经济的行业中，大厂商比小厂商更具有成本优 势，就形成不完全竞争的市场结构。 克鲁格曼:《国际经济学》(中本版)p.115~116