1. This figure is copied from Borchert and Adams,op., cit. John R. Borchert and Russell B. Adams,Trade Centers and Trade Areas of the Upper Midwest, Upper Midwest Economic Study, Urban Report No. 3, September, 1963, p. 4.
2. W. W. Leontief “Introduction to a Theory of the Internal Structure of Functional Relationships,”Econometrica, XV, No. 4, (1947), pp. 361–73 (see page 371). Robert H. Strotz, “The Empirical Implications of a Utility Tree,”Econometrica, XXV, No. 2, (1957), pp. 269–80. W. M. Gorman pointed out an error in Strotz's presentation which was followed by a correction by Strotz. See, W. M. Gorman, “Separable Utility and Aggregation,”Econometrica, XXVII, (1959), pp. 469–81, and Robert H. Strotz, “The Utility Tree—A Correction and Further Appraisal,”Econometrica, XXVII, (1959), pp. 482–88.
3. Ragnar Frisch, “A Complete Scheme for Computing All Direct and Cross Demand Elasticities in a Model with Many Sectors,”Econometrica, XXVII, (1959), pp. 177–96.
4. Contributions to Economic Analysis;H. Theil,1958
5. —,Optimal Decision Rules for Government and Industry, Studies in Mathematical and Managerial Economics, (Amsterdam: North-Holland Publishing Company and Chicago: Rand McNally & Company, 1964).