phù hợp với một khuôn mẫu nhất định, một số tính năng khác cũng phải có mặt, sự hiện diện của họ là "deducible" từ các mô hình giả định ban đầu. Các phương pháp phân tích chỉ đơn giản là một cách để khám phá ra những hậu quả cần thiết của collocations phức tạp của thực tế | 122 SIGNIFICANCE OF ECONOMIC SCIENCE CH. conforms to a certain pattern certain other features must also be present for their presence is deducible from the pattern originally postulated. The analytic method is simply a way of discovering the necessary consequences of complex collocations of facts consequences whose counterpart in reality is not so immediately discernible as the counterpart of the original postulates. It is an instrument for shaking out all the implications of given suppositions. Granted the correspondence of its original assumptions and the facts its conclusions are inevitable and inescapable. All this becomes particularly clear if we consider the procedure of diagrammatic analysis. Suppose for example we wish to exhibit the effects on price of the imposition of a small tax. We make certain suppositions as regards the elasticity of demand certain suppositions as regards the cost functions embody these in the usual diagram and we can at once read off as it were the effects on the They are implied in the original suppositions. The diagram has simply made explicit the concealed implications. It is this inevitability of economic analysis which gives it its very considerable prognostic value. It has been emphasised sufficiently already that Economic Science knows no way of predicting out of the blue the configuration of the data at any particular point of time. It cannot predict changes of valuations. But given the data in a particular situation it can draw inevitable conclusions as to their implications. And if the data remain unchanged these implications will certainly be realised. They must be for they are implied in the presence of the original data. 1 See . Dalton Public Finance 2nd edition p. 73. V ECONOMIC GENERALISATIONS AND REALITY 123 It is just here that we can perceive yet a further function for empirical investigation. It can bring to light the changing facts which make prediction in any given situation possible. As we have seen