But if the capitalists of Department I wish to accumulate half their surplus value (1,000) and to consume the other half, they need consumer goods for themselves and for their workers to the tune of 1,500 units which they can obtain only from Department II in exchange for their own products—means of production. Since Department II has already satisfied its own demand for producer goods to the extent of its own constant capital (1,430), this exchange is only possible if Department II decides to enlarge its own constant capital by 70. This means that it must enlarge its own production—and it can do so only by capitalising a corresponding part of its surplus value. If this surplus value amounts to 285 in Department II, 70 of it must be added to the constant capital. The first step towards expansion of production in Department II is thus demonstrated to be at the same time the condition for, and the consequence of, increased consumption by the capitalists of Department I. But to proceed. Hitherto, the capitalists of Department I could only spend one-half of their surplus value (500) on personal consumption. To capitalise the other half, they must redistribute these 500s in such a way as to maintain at least the previous ratio of composition, i.e. they must increase the constant capital by 417 and the variable capital by 83. The first operation presents no difficulties: the surplus value of 500 belonging to the capitalists of Department I is contained in a natural form in their own product, the means of production, and is fit straightway to enter into the process of production; Department I can therefore enlarge its constant capital with the appropriate quantity of its own product. But the remaining 83 can only be used as variable capital if there is a corresponding quantity of consumer goods for the newly employed workers. Here it becomes evident for the second time that accumulation in Department I is dependent upon Department II: Department I must receive for its workers 83 more consumer goods than before from Department II. As this is again possible only by way of commodity exchange, Department I can satisfy its demands only on condition that Department II is prepared for its part to take up products of Department I, producer goods, to the tune of 83. Since Department II has no use for the means of production except to employ them in the process of production, it becomes not only possible but even necessary that Department II should increase its own constant capital by these very 83 which will now be used for capitalisation and are thus again withdrawn from the consumable surplus value of this department. The increase in the variable capital of Department I thus entails the second step in the enlargement of production in Department II. All material prerequisites of accumulation in Department I are now present and enlarged reproduction can proceed. Department II, however, has so far made only two increases in its constant capital. The result of this enlargement is that if the newly acquired means of production are indeed to be used, the quantity of labour power must be increased correspondingly. Maintaining the previous ratio, the new constant capital of 153 requires a new variable capital of 31. This implies the necessity to capitalise a corresponding further amount of the surplus value. Thus the fund for the capitalists’ personal consumption in Department II comes to be what remains of the surplus value (285s) after deduction of the amounts used for twice enlarging the constant capital (70 + 83) and a commensurate increase in the variable capital (31)—a fund of 101, after deducting a total of 184. Similar operations in the second year of accumulation result for Department II in its surplus value being divided into 158 for capitalisation and 158 for the consumption of its capitalists, and in the third year, the figures become 172 and 170 respectively.

We have studied this process so closely, tracing it step by step, because it shows clearly that the accumulation of Department II is completely determined and dominated by the accumulation of Department I. Though this dependence is no longer expressed, as in Marx’s first example, by arbitrary changes in the distribution of the surplus value, it does not do away with the fact itself, even if now the surplus value is always neatly halved by each department, one-half for capitalisation and the other for personal consumption. Though there is nothing to choose between the capitalists of the two departments as far as the figures are concerned, it is quite obvious that Department I has taken the initiative and actively carries out the whole process of accumulation, while Department II is merely a passive appendage. This dependence is also expressed in the following precise rule: accumulation must proceed simultaneously in both departments, and it can do so only on condition that the provisions-department increases its constant capital by the precise amount by which the capitalists of the means-of-production-department increase both their variable capital and their fund for personal consumption. This equation (increase IIc = increase Iv + increase Is.c.)[106] is the mathematical cornerstone of Marx’s diagram of accumulation, no matter what figures we may choose for its concrete application. But now we must see whether capitalist accumulation does in actual fact conform to this hard and fast rule.

Let us first return to simple reproduction. Marx’s diagram, it will be remembered, was as follows:

I.4,000c+1,000v+1,000s=6,000means of production
II.2,000c+500v+500s=3,000means of consumption
9,000total production

Here, too, we established certain equations which form the foundation of simple reproduction; they were:

(a) The product of Department I equals in value the sum of the two constant capitals in Departments I and II.

(b) The constant capital of Department II equals the sum of variable capital and surplus value in Department I—a necessary consequence of (a).

(c) The product of Department II equals the sum of variable capital and surplus value in both departments—a necessary consequence of (a) and (b).

These equations correspond to the conditions of capitalist commodity production (at the restricted level of simple reproduction, however). Equation (b), for instance, is a result of the production of commodities, entailed by the fact, in other words, that the entrepreneurs of either department can only obtain the products of the other by an exchange of equivalents. Variable capital and surplus value in Department I together represent the demand of this department for consumer goods. The product of Department II must provide for the satisfaction of this demand, but consumer goods can only be obtained in exchange for an equivalent part of the product of Department I, the means of production. These equivalents, useless to Department II in their natural form if not employed as constant capital in the process of production, will thus determine how much constant capital there is to be in Department II. If this proportion were not adhered to, if, e.g., the constant capital of Department II (as a quantity of value) were larger than I(v + s), then it could not be completely transformed into means of production, since the demand of Department I for consumer goods would be too small; if the constant capital (II) were smaller than I(v + s.c), either the previous quantity of labour power could not be employed in this department, or the capitalists could not consume the whole of their surplus value. In all these cases, the premises of simple reproduction would be violated.

These equations, however, are not just an exercise in mathematics, nor do they merely result from the system of commodity production. To convince us of this fact, there is a simple means at hand. Let us imagine for a moment that, instead of a capitalist method of production, we have a socialist, i.e. a planned society in which the social division of labour has come to replace exchange. This society also will divide its labour power into producers of means of production and producers of means of consumption. Let us further imagine the technical development of labour to be such that two-thirds of social labour are employed in the manufacture of producer goods and one-third in the manufacture of consumer goods. Suppose that under these conditions 1,500 units (reckoned on a daily, monthly, or yearly basis) suffice to maintain the whole working population of the society, one thousand of these being employed, according to our premise, in Department soc. I (making means of production), and five hundred in Department soc. II (making consumer goods), and that the means of production dating from previous labour periods and used up during one year’s labour, represent 3,000 labour units. This labour programme, however, would not be adequate for the society, since considerably more labour will be needed to maintain all those of its members who do not work in the material, the productive sense of the term: the child, the old and sick, the civil servant, the artist and the scientist. Moreover, every society needs certain reserves against a rainy day, as a protection against natural calamities. Taking it that precisely the same quantity of labour and, similarly, of means of production as that required for the workers’ own maintenance is needed to maintain all the non-workers and to build up the reserves, then, from the figures previously assumed, we should get the following diagram for a regulated production: