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The Purchasing Power of Money
CHAPTER II
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| 200,000,000 loaves of bread at | $ .10 a loaf, |
| 10,000,000 tons of coal at | 5.00 a ton, and |
| 30,000,000 yards of cloth at | 1.00 a yard. |
The value of these transactions is evidently $100,000,000, i.e. $20,000,000 worth of bread plus $50,000,000 worth of coal plus $30,000,000 worth of cloth. The equation of exchange therefore (remember that the money side consisted of $5,000,000 exchanged 20 times) is as follows:—
| $5,000,000 × 20 times a year | |
| = 200,000,000 loaves × $ .10 a loaf | |
| + 10,000,000 tons × 5.00 a ton | |
| + 30,000,000 yards × 1.00 a yard. |
This equation contains on the money side two magnitudes, viz. (1) the quantity of money and (2) its velocity of circulation; and on the goods side two groups of magnitudes in two columns, viz. (1) the quantities of goods exchanged (loaves, tons, yards), and (2) the prices of these goods. The equation shows that these four sets of magnitudes are mutually related. Because this equation must be fulfilled, the prices must bear a relation to the three other sets of magnitudes,—quantity of money, rapidity of circulation, and quantities of goods exchanged. Consequently, these prices must, as a whole, vary proportionally with the quantity of money and with its velocity of circulation, and inversely with the quantities of goods exchanged.
Suppose, for instance, that the quantity of money were doubled, while its velocity of circulation and the quantities of goods exchanged remained the same. Then it would be quite impossible for prices to remain unchanged. The money side would now be $10,000,000 × 20 times a year or $200,000,000; whereas, if prices should not change, the goods would remain $100,000,000, and the equation would be violated. Since exchanges, individually and collectively, always involve an equivalent quid pro quo, the two sides must be equal. Not only must purchases and sales be equal in amount—since every article bought by one person is necessarily sold by another—but the total value of goods sold must equal the total amount of money exchanged. Therefore, under the given conditions, prices must change in such a way as to raise the goods side from $100,000,000 to $200,000,000. This doubling may be accomplished by an even or uneven rise in prices, but some sort of a rise of prices there must be. If the prices rise evenly, they will evidently all be exactly doubled, so that the equation will read:—
| $10,000,000 × 20 times a year | |
| = 200,000,000 loaves × $ .20 per loaf | |
| + 10,000,000 tons × 10.00 per ton | |
| + 30,000,000 yards × 2.00 per yard. |
If the prices rise unevenly, the doubling must evidently be brought about by compensation; if some prices rise by less than double, others must rise by enough more than double to exactly compensate.
But whether all prices increase uniformly, each being exactly doubled, or some prices increase more and some less (so as still to double the total money value of the goods purchased), the prices are doubled on the average.*15 This proposition is usually expressed by saying that the "general level of prices" is raised twofold. From the mere fact, therefore, that the money spent for goods must equal the quantities of those goods multiplied by their prices, it follows that the level of prices must rise or fall according to changes in the quantity of money, unless there are changes in its velocity of circulation or in the quantities of goods exchanged.
If changes in the quantity of money affect prices, so will changes in the other factors—quantities of goods and velocity of circulation—affect prices, and in a very similar manner. Thus a doubling in the velocity of circulation of money will double the level of prices, provided the quantity of money in circulation and the quantities of goods exchanged for money remain as before. The equation will become:—
| $5,000,000 × 40 times a year | |
| = 200,000,000 loaves × $ .20 a loaf | |
| + 10,000,000 tons × 10.00 a ton | |
| + 30,000,000 yards × 2.00 a yard, |
or else the equation will assume a form in which some of the prices will more than double, and others less than double by enough to preserve the same total value of the sales.
Again, a doubling in the quantities of goods exchanged will not double, but halve, the height of the price level, provided the quantity of money and its velocity of circulation remain the same. Under these circumstances the equation will become:—
| $5,000,000 × 20 times a year | |
| = 400,000,000 loaves × $ .05 a loaf | |
| + 20,000,000 tons × 2.50 a ton | |
| + 60,000,000 yards × .50 a yard, |
or else it will assume a form in which some of the prices are more than halved, and others less than halved, so as to preserve the equation.
Finally, if there is a simultaneous change in two or all of the three influences, i.e. quantity of money, velocity of circulation, and quantities of goods exchanged, the price level will be a compound or resultant of these various influences. If, for example, the quantity of money is doubled, and its velocity of circulation is halved, while the quantity of goods exchanged remains constant, the price level will be undisturbed. Likewise, it will be undisturbed if the quantity of money is doubled and the quantity of goods is doubled, while the velocity of circulation remains the same. To double the quantity of money, therefore, is not always to double prices. We must distinctly recognize that the quantity of money is only one of three factors, all equally important in determining the price level.
The equation of exchange has now been expressed by an arithmetical illustration. It may be also represented visually, by a mechanical illustration. Such a representation is embodied in Figure 2. This represents a mechanical balance in equilibrium, the two sides of which symbolize respectively the money side and the goods side of the equation of exchange. The weight at the left, symbolized by a purse, represents the money in circulation; the "arm" or distance from the fulcrum at which this weight (purse) is hung represents the efficiency of this money, or its velocity of circulation. On the right side are three weights,—bread, coal, and cloth, symbolized respectively by a loaf, a coal scuttle, and a roll of cloth. The arm, or distance of each from the fulcrum, represents its price. In order that the lever arms at the right may not be inordinately long, we have found it convenient to reduce the unit of measure of coal from tons to hundredweights, and that of cloth from yards to feet, and consequently to enlarge correspondingly the numbers of units (the measure of coal changing from 10,000,000 tons to 200,000,000 hundred-weights, and that of the cloth from 30,000,000 yards to 90,000,000 feet). The price of coal in the new unit per hundredweight becomes 25 cents per hundredweight, and that of cloth in feet becomes 33 1/3 cents per foot.
We all know that, when a balance is in equilibrium, the tendency to turn in one direction equals the tendency to turn in the other. Each weight produces on its side a tendency to turn, measured by the product of the weight by its arm. The weight on the left produces, on that side, a tendency measured by 5,000,000 × 20; while the weights on the right make a combined opposite tendency measured by 200,000,000×.10+200,000,000×.25+90,000,000×.33 1/3. The equality of these opposite tendencies represents the equation of exchange.
An increase in the weights or arms on one side requires, in order to preserve equilibrium, a proportional increase in the weights or arms on the other side. This simple and familiar principle, applied to the symbolism here adopted, means that if, for instance, the velocity of circulation (left arm) remains the same, and if the trade (weights at the right) remains the same, then any increase of the purse at the left will require a lengthening of one or more of the arms at the right, representing prices. If these prices increase uniformly, they will increase in the same ratio as the increase in money; if they do not increase uniformly, some will increase more and some less than this ratio, maintaining an average.
Likewise it is evident that if the arm at the left lengthens, and if the purse and the various weights on the right remain the same, there must be an increase in the arms at the right.
Again, if there is an increase in weights at the right, and if the left arm and the purse remain the same, there must be a shortening of right arms.
In general, a change in one of the four sets of magnitudes must be accompanied by such a change or change in one or more of the other three as shall maintain equilibrium.
As we are interested in the average change in prices rather than in the prices individually, we may simplify this mechanical representation by hanging all the right-hand weights at one average point, so that the arm shall represent the average prices. This arm is a "weighted average" of the three original arms, the weights being literally the weights hanging at the right.
This averaging of prices is represented in Figure 3, which visualizes the fact that the average price of goods (right arm) varies directly with the quantity of money (left weight), and directly with its velocity of circulation (left arm), and inversely with the volume of trade (right weight).
We now come to the strict algebraic statement of the equation of exchange. An algebraic statement is usually a good safeguard against loose reasoning; and loose reasoning is chiefly responsible for the suspicion under which economic theories have frequently fallen. If it is worth while in geometry to demonstrate carefully, at the start, propositions which are almost self-evident, it is a hundredfold more worth while to demonstrate with care the propositions relating to price levels, which are less self-evident; which, indeed, while confidently assumed by many, are contemptuously rejected by others.
Let us denote the total circulation of money, i.e. the amount of money expended for goods in a given community during a given year, by E (expenditure); and the average amount of money in circulation in the community during the year by M (money). M will be the simple arithmetical average of the amounts of money existing at successive instants separated from each other by equal intervals of time indefinitely small. If we divide the year's expenditures, E, by the average amount of money, M, we shall obtain what is called the average rate of turnover of money in its exchange for goods, E/M, that is, the velocity of circulation of money.*16 This velocity may be denoted by V, so that E/M = V; then E may be expressed as MV. In words: the total circulation of money in the sense of money expended is equal to the total money in circulation multiplied by its velocity of circulation or turnover. E or MV, therefore, expresses the money side of the equation of exchange. Turning to the goods side of the equation, we have to deal with the prices of goods exchanged and quantities of goods exchanged. The average*17 price of sale of any particular good, such as bread, purchased in the given community during the given year, may be represented by p (price); and the total quantity of it purchased, by Q (quantity); likewise the average price of another good (say coal) may be represented by p' and the total quantity of it exchanged, by Q'; the average price and the total quantity of a third good (say cloth) may be represented by p'' and Q'' respectively; and so on, for all other goods exchanged, however numerous. The equation of exchange may evidently be expressed as follows: *18—
The right-hand side of this equation is the sum of terms of the form pQ—a price multiplied by a quantity bought. It is customary in mathematics to abbreviate such a sum of terms (all of which are of the same form) by using "S" as a symbol of summation. This symbol does not signify a magnitude as do the symbols M, V, p, Q, etc. It signifies merely the operation of addition and should be read "the sum of terms of the following type." The equation of exchange may therefore be written:—
That is, the magnitudes E, M, V, the p's and the Q's relate to the entire community and an entire year; but they are based on and related to corresponding magnitudes for the individual persons of which the community is composed and for the individual moments of time of which the year is composed.*19
The algebraic derivation of this equation is, of course, essentially the same as the arithmetical derivation previously given. It consists simply in adding together the equations for all individual purchases within the community during the year.*20
By means of this equation, MV = SpQ, the three theorems set forth earlier in this chapter may be now expressed as follows:—
(1) If V and the Q's remain invariable while M varies in any ratio, the money side of the equation will vary in the same ratio and therefore its equal, the goods side, must vary in that same ratio also; consequently, either the p's will all vary in that ratio or else some p's will vary more than in that ratio and others enough less to compensate and maintain the same average.*21
(2) If M and the Q's remain invariable while V varies in any ratio, the money side of the equation will vary in the same ratio, and therefore its equal, the goods side, must vary in that ratio also; consequently, the p's will all vary in the same ratio or else some will vary more and others enough less to compensate.
(3) If M and V remain invariable, the money side and the goods side will remain invariable; consequently, if the Q's all vary in a given ratio, either the p's must all vary in the inverse ratio or else some of them will vary more and others enough less to compensate.
We may, if we wish, further simplify the right side by writing it in the form PT where P is a weighted average of all the p's, and T is the sum of all the Q's. P then represents in one magnitude the level of prices, and T represents in one magnitude the volume of trade. This simplification is the algebraic interpretation of the mechanical illustration given in Figure 3, where all the goods, instead of being hung separately, as in Figure 2, were combined and hung at an average point representing their average price.
We have derived the equation of exchange, MV = SpQ, by adding together, for the right side, the sums expended by different persons. But the same reasoning would have derived an equation of exchange by taking the sums received by different persons. The results of the two methods will harmonize if the community has no foreign trade; for, apart from foreign trade, what is expended by one person in the community is necessarily received by some other person in that community.
If we wish to extend the reasoning so as to apply to foreign trade, we shall have two equations of exchange, one based on money expended and the other on money received or accepted by members of the community. These will always be approximately equal and may or may not be exactly equal within a country according to the "balance of trade" between that country and others. The right side of the equation based on expenditures will include, in addition to the domestic quantities already represented there, the quantities of goods imported and their prices, but not those exported; while the reverse will be true of the equation based on receipts.
This completes our statement of the equation of exchange, except for the element of check payments, which is reserved for the next chapter. We have seen that the equation of exchange has as its ultimate basis the elementary equations of exchange pertaining to given persons and given moments, in other words, the equations pertaining to individual transactions. Such elementary equations mean that the money paid in any transaction is the equivalent of the goods bought at the price of sale. From this secure and obvious premise is derived the equation of exchange MV = SpQ, each element in which is a sum or an average of the like elementary elements for different individuals and different moments, thus comprising all the purchases in the community during the year. Finally, from this equation we see that prices vary directly as M and V, and inversely as the Q's, provided in each case only one of these three sets of magnitudes varies, and the other two remain unchanged. Whether to change one of the three necessarily disturbs the others is a question reserved for a later chapter. Those who object to the equation of exchange as a mere truism are asked to defer judgment until they have read Chapter VIII.
To recapitulate, we find then that, under the conditions assumed, the price level varies (1) directly as the quantity of money in circulation (M), (2) directly as the velocity of its circulation (V), (3) inversely as the volume of trade done by it (T). The first of these three relations is worth emphasis. It constitutes the "quantity theory of money."
So important is this principle, and so bitterly contested has it been, that we shall illustrate it further. As already indicated, by "the quantity of money" is meant the number of dollars (or other given monetary units) in circulation. This number may be changed in several ways, of which the following three are most important. Their statement will serve to bring home to us the conclusions we have reached and to reveal the fundamental peculiarity of money on which they rest.
As a first illustration, let us suppose the government to double the denominations of all money; that is, let us suppose that what has been hitherto a half dollar is henceforth called a dollar, and that what has hitherto been a dollar is henceforth called two dollars. Evidently the number of "dollars" in circulation will then be doubled; and the price level, measured in terms of the new "dollars," will be double what it would otherwise be. Every one will pay out the same coins as though no such law were passed. But he will, in each case, be paying twice as many "dollars." For example, if $3 formerly had to be paid for a pair of shoes, the price of this same pair of shoes will now become $6. Thus we see how the nominal quantity of money affects price levels.
A second illustration is found in a debased currency. Suppose a government cuts each dollar in two, coining the halves into new "dollars"; and, recalling all paper notes, replaces them with double the original number—two new notes for each old one of the same denomination. In short, suppose money not only to be renamed, as in the first illustration, but also reissued; prices in the debased coinage will again be doubled just as in the first illustration. The subdivision and recoinage is an immaterial circumstance, unless it be carried so far as to make counting difficult and thus to interfere with the convenience of money. Wherever a dollar had been paid before debasement, two dollars—i.e. two of the old halves coined into two of the new dollars—will now be paid instead.
In the first illustration, the increase in quantity was simply nominal, being brought about by renaming coins. In the second illustration, besides renaming, the further fact of recoining is introduced. In the first case the number of actual pieces of money of each kind was unchanged, but their denominations were doubled. In the second case, the number of pieces is also doubled by splitting each coin and reminting it into two coins, each of the same nominal denomination as the original whole of which it is the half, and by similarly redoubling the paper money.
For a third illustration, suppose that, instead of doubling the number of dollars by splitting them in two and recoining the halves, the government duplicates each piece of money in existence and presents the duplicate to the possessor of the original.*22 (We must in this case suppose, further, that there is some effectual bar to prevent the melting or exporting of money. Otherwise the quantity of money in circulation will not be doubled: much of the increase will escape.) If the quantity of money is thus doubled, prices will also be doubled just as truly as in the second illustration, in which there were exactly the same denominations. The only difference between the second and the third illustrations will be in the size and weight of the coins. The weights of the individual coins, instead of being reduced, will remain unchanged; but their number will be doubled. This doubling of coins must have the same effect as the 50 per cent debasement, i.e. it must have the effect of doubling prices.
The force of the third illustration becomes even more evident if, in accordance with Ricardo's presentation,*23 we pass back by means of a seigniorage from the third illustration to the second. That is, after duplicating all money, let the government abstract half of each coin, thereby reducing the weight to that of the debased coinage in the second illustration, and removing the only point of distinction between the two. This "seigniorage" abstracted will not affect the value of the coins, so long as their number remains unchanged.
In short, the quantity theory asserts that (provided velocity of circulation and volume of trade are unchanged) if we increase the number of dollars, whether by renaming coins, or by debasing coins, or by increasing coinage, or by any other means, prices will be increased in the same proportion. It is the number, and not the weight, that is essential. This fact needs great emphasis. It is a fact which differentiates money from all other goods and explains the peculiar manner in which its purchasing power is related to other goods. Sugar, for instance, has a specific desirability dependent on its quantity in pounds. Money has no such quality. The value of sugar depends on its actual quantity. If the quantity of sugar is changed from 1,000,000 pounds to 1,000,000 hundredweight, it does not follow that a hundredweight will have the value previously possessed by a pound. But if money in circulation is changed from 1,000,000 units of one weight to 1,000,000 units of another weight, the value of each unit will remain unchanged.
The quantity theory of money thus rests, ultimately, upon the fundamental peculiarity which money alone of all goods possesses,—the fact that it has no power to satisfy human wants except a power to purchase things which do have such power.*24
Notes for Chapter III
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