[2] Seligman, E. R. A., _Principles of Economics_, New York, 1905, especially pp. 179-82 and 192-93. Bullock, C. J., _Introduction to the Study of Economics_, especially pp. 162-64. There is no attempt at a psychological treatment in this work, and no clear statement of the meaning of the concept, social. Kinley, David, _Money_, New York, 1904, pp. 125-26. The social value conception runs through the book. Merriam, L. S., "The Theory of Final Utility in its Relation to Money and the Standard of Deferred Payments," _Annals of the American Academy_, vol. III; "Money as a Measure of Value," _ibid._, vol. IV; an unfinished study in the same volume, pp. 969-72, described by Professor J. B. Clark. Ross, E. A., "The Standard of Deferred Payments," _ibid._, vol. III; "The Total Utility Standard of Deferred Payments," _ibid._, vol. IV. These articles by Professors Ross and Merriam were written in the course of an interesting controversy between the gentlemen named, Tuttle, C. A., "The Wealth Concept," ibid., vol. I; "The Fundamental Economic Principle," _Quarterly Journal of Economics_, 1901. [3] See chapter XII. [4] See especially Professor Clark's _Essentials of Economic Theory_, New York, 1907, pp. 41-42. [5] See especially _The Philosophy of Wealth_, 1892 ed., pp. 73-74. [6] _Principles_, pp. 179-82. [7] The general references for Ross and Merriam have been given _supra._ _Cf._ p. 62 of Dean Kinley's _Money_. [8] "Ultimate Standard of Value." This article is substantially the same as chap, XXIV of _The Distribution of Wealth_, New York, 1899. [9] In his discussion of social value in the _Principles_, Professor Seligman modifies a statement made in his article, "Social Elements in the Theory of Value" (_Quarterly Journal of Economics_, vol. XV). The two discussions are parallel in part, the former being based upon the latter. The passage quoted is from the _Q. J. E._ article, pp. 323-24. The same passage is essentially reproduced in the _Principles_ (first edition, p. 180), with the exception of the passages in italics: "I not only measure the relative satisfaction that I can get from apples or nuts, but the quantity of apples I can get for the nuts depends upon the relative estimate put upon them by the rest of society. _Some individuals may prize a commodity a little more, some a little less; but its real value is the average estimate, the estimate of what society thinks it is worth._ If an apple is worth twice as much as a nut, it is only because the community, after comparing _and averaging_ individual preferences," etc. The conception of social value as an _average_ of individual values is withdrawn in the second treatment, and no substitute is offered for it.