Now capital is accumulated with the object of a certain return as the reward of accumulation. Instead of spending his money, a man saves it with the object of retaining as the result of that saving a certain yearly revenue. The measure of this does not fall in a particular society at a particular time below a certain level. In other words, if a man cannot get a certain minimum reward for his accumulation, he will not accumulate but spend. What is called in economics "The Law of Diminishing Returns" acts so that continual additions to capital, other things being equal (that is, the methods of production remaining the same), do not provide a corresponding increase of revenue. A thousand measures of capital applied to a particular area of natural forces will produce, for instance, 40 measures yearly, or 4 per cent.; but 2000 measures applied in the same fashion will not produce 80 measures. They will produce more than the thousand measures did, but not more in proportion; not double. They will produce, say, 60 measures, or 3 per cent., upon the capital. The action of this universal principle automatically checks the accumulation of capital when it has reached such a point that the proportionate return is the least which a man will accept. If it falls below that he will spend rather than accumulate. The limit of this minimum in any particular society at any particular time gives the measure to what we call "_the Effective Desire of Accumulation_." Thus in England to-day it is a little over 3 per cent. The minimum which limits the accumulation of capital is a minimum return of about one-thirtieth yearly upon such capital, and this we may call for shortness the "E.D.A." of our society at the present time. When, therefore, the Capitalist estimates the full value of his possessions, he counts them in "so many years' purchase."[6] And that means that he is willing to take in a lump sum down for his possessions so many times the yearly revenue which he at present enjoys. If his E.D.A. is one-thirtieth, he will take a lump sum representing thirty times his annual revenue. So far so good. Let us suppose the two Capitalists in our example to have an E.D.A. of one-thirtieth. They will sell to the State if the State can put up 3000 measures of wheat. Now, of course, the State can do nothing of the kind. The accumulations of wheat being already in the hands of the Capitalists, and those accumulations amounting to much less than 3000 measures of wheat, the thing appears to be a deadlock. But it is not a deadlock if the Capitalist is a fool. The State can go to the Capitalists and say: "Hand me over your farms, and against them I will give you guarantee that you shall be paid _rather more than_ 100 measures of wheat a year for the thirty years. In fact, I will pay you half as much again until these extra payments amount to a purchase of your original stock." Out of what does this extra amount come? Out of the State's power to tax.