The other side of this picture of continual changes in the relation between the portions of constant and variable capital is the formation of a relative surplus population, as Marx called it, that is to say that part of the working population which exceeds the average needs of capital, and thus becomes redundant. This reserve of unemployable industrial labour (taken here in a broader sense, and including a proletariat that is dominated by merchant capital) is always present. It forms a necessary prerequisite of the sudden expansion of production in times of boom, and is another specific condition of capitalist accumulation.[99] From the accumulation of individual capitals we can therefore deduce the following four characteristic phenomena of enlarged reproduction: (1) The volume of enlarged reproduction is independent, within certain limits, of the growth of capital, and can transcend it. The necessary methods for achieving this are: increased exploitation of labour and natural forces, and increased labour productivity (including increased efficiency of the fixed capital). (2) All real accumulation starts with that part of the surplus value which is intended for capitalisation being divided into constant and variable capital. (3) Accumulation as a social process is accompanied by continuous changes in the relation between constant and variable capital, whereby that portion of capital which is invested in inanimate means of production continually increases as compared with that expended on wages. (4) Concomitant with the accumulative process, and as a condition of the latter, there develops an industrial reserve army. These characteristics, derived from the reproductive process as it is performed by the individual capitals, represent an enormous step forward as compared with the analyses of bourgeois economists. Now, however, our problem is to demonstrate the accumulation of the aggregate capital which originates from these movements of individual capitals, and on the basis of the diagram of simple reproduction to establish the precise relations between the aspects of value prevalent in the production of surplus value and the material considerations in the production of consumer and producer goods, with a view to accumulation. The essential difference between enlarged reproduction and simple reproduction consists in the fact that in the latter the capitalist class and its hangers-on consume the entire surplus value, whereas in the former a part of the surplus value is set aside from the personal consumption of its owners, not for the purpose of hoarding, but in order to increase the active capital, i.e. for capitalisation. To make this possible, the new additional capital must also find the material prerequisites for its activity forthcoming. Here the concrete composition of the aggregate social product becomes important. Marx says already in volume i, when he considers the accumulation of individual capitals: