producers make enough to supply the want of a particular group of persons to whom it is a marginal service and who are willing to pay only what it costs. They would go without that one service if they had to pay more for it. _This Method of Valuation Applicable to All Commodities of High Grade._--Illustrations of this principle might be multiplied indefinitely. A fine watch tells the time of day, but something that would do that could be had for a dollar, and that is all that this fundamental element in the fine watch sells for. It takes a series of purchasers bidding on the higher utilities of the fine watch to make it sell for five hundred dollars. The man who buys such a watch would give, perhaps, ten thousand for it rather than be without a watch altogether, but he is saved from the necessity of doing so by the fact that poorer customers have done the appraising in the case of all the more fundamental qualities which the watch possesses. So long as an Ingersoll "dollar watch" will tell the time of day, no one will pay more than a dollar for exactly that same service rendered by any watch whatever; and the same thing is true of other services. Social in a very concrete and literal sense is the operation of fixing prices. Only the simplest and cheapest things that are sold in the market at all bring just what they are worth to the buyers, and all articles of higher grade offer to all who buy them a surplus of service not offset by what is paid for them. If we rule out the cheapest and poorest grades of articles, we find all others affording a "consumers' surplus."[2] [2] It will be seen that to a man who buys the seventy-five dollar coat that article in its entirety is the final one of its kind which he will buy. He does not want a second coat exactly like the first. The same thing is true of the man who buys the five hundred dollar watch, since he does not think of buying more than one. In each case the first unit of the article bought is the last one, and it contains utilities which are worth more than they cost. It contains one utility only which is marginal in the true sense of affording no surplus of gain above cost. This utility stands on the boundary line where consumers' surpluses stop. CHAPTER VII NORMAL VALUE