one is concerned with the interplay between economies of scale and an anticipated persistent growth in demand for capacity. The generalizations discussed here are of two types: (a) the use of probabilities in place of a constant rate of growth in demand; and (b) a study of the economies and the penalties involved in accumulating backlogs of unsatisfied demand. The possibility of accumulating such backlogs raises considerable doubt with respect to Chenery's excess capacity hypothesis. Surprisingly enough, generalization (b) leads to greater difficulties in analysis than (a). The use of probabilities to describe the growth process does little-if anything-to complicate matters. A probabilistic version of Chenery's model turns out to be closely related to the classical problem of gambler's ruin, and a powerful tool can be borrowed from that area-the Laplace transform for the duration of the game. Thanks to this transform, the zero-backlog probabilistic model becomes no more difficult to study than the corresponding deterministic one. A direct implication is that a probabilistic growth course makes it necessary to incur higher expected costs, and also makes it desirable to install plant capacity of a somewhat larger size than would be optimal if demand were growing at a steady rate equal to the expected value of the probabilistic increments. Uncertainty, in this sense, has a stimulating effect upon the magnitude of individual investments.

T HERE is general agreement that nineteenth century was unparalleled in growth of large-scale production. However, fate of scale of production in twentieth century seems to be lost in a limbo of uncertainty. One investigator comments that the movement towards large-scale production is largely a nineteenth century phenomenon and had run its course by i890. 1 Another commentator holds that size is growing with great rapidity. 2 Yet again we read that long-term, general and pervasive increase in plant size throughout most industries has come to an end. I It is purpose of this paper to present some empirical evidence on changes in scale of production in United States manufacturing industry. By scale of production we refer to size of plant rather than size of firm. The very notion of scale of production implies a relationship between volume of output and unit costs. Where economies of scale bear upon questions of monopoly, problem is one of control of output. Hence, scale of production is measured in this paper by physical output per establishment. Indexes of physical output are available for United States manufacturing industry, permitting construction of indexes of scale of production as measured by an index of output per establishment.4 To measure scale by number of employees would tend to underestimate industrial expansion linked with labor-saving innovations.5 Similarly, trends in ratio of value-added or capital per establishment may diverge significantly from movement of scale. In addition, data from which indexes of value-added can be constructed are not available for a sufficient period of time to be useful while records of capital value are flagrantly unreliable in that they are subject to judgment of person making estimate and to vagaries of longand short-term fluctuations in prices. The interpretation of long-term movements in indexes of output per establishment as changes in optimal plant size need not be vitiated by assumption of an optimum range of output rather than an optimum point.

(e) Net interest paid by government. The national income net interest total comprises total interest accruing to United States persons and governments less the total interest paid by United States governments to persons, governments, and businesses. The personal income interest total is obtained by adding to the national figure the excess of interest payments by governments over their interest receipts. Thus it measures total interest paid to United States persons.3 The share of the national total attributable to any one state is extremely difficult, if not impossible, to estimate by direct means, if this were desired. But allocation can be made more easily, although the method rests upon the same sort of fundamental and hazardous assumptions as in the case of allocating corporate income. Figures are availalble from the Department of Commerce of private interest received by residents of Texas and the United States. The Texas state income component of United States net interest paid by governments was obtained by applying the ratio obtained from the private interest figures to the United States net government interest total. The assumption here, of course, is that Texas residents' entitlement to a share of the national total of net government interest was the same as their entitlement to a share of the national total of private interest, as reflected in the payments actually made or imputed. The method also, as in the corporate income case, has the merit of conforming to the conceptual framework which emphasizes the wherereceived measure. TABLE 4.-GOVERNMENT AND BUSINESS TRANSFER PAYMENTS, TEXAS, I950-58 ($ million)

A. S. Goldberger, A. L. Nagar, H. S. Odeh, The Covariance Matrices of Reduced-Form Coefficients and of Forecasts for a Structural Econometric Model, Econometrica, Vol. 29, No. 4 (Oct., 1961), pp. 556-573

Reviews the book "Accounting Manual for Export-Import Companies," by Jack Goldner.

Reviews the book "Executive Action Simulation," by Lowell W. Harron.