Rosa Luxemburg garbles this argument considerably, and brushes it away as beside the point. And it _is_ beside the point that she is concerned with. She does not admit the savings and investment problem, for she takes it for granted that each individual act of saving out of surplus is accompanied by a corresponding amount of real investment, and that every piece of investment is financed by saving out of surplus of the same capitalist who makes it.[29] What she appears to be concerned with is rather the inducement to invest. What motive have the capitalists for enlarging their stock of real capital?[30] How do they know that there will be demand for the increased output of goods which the new capital will produce, so that they can 'capitalise' their surplus in a profitable form? (On the purely analytical plane her affinity seems to be with Hobson rather than Keynes.) Needless to say, our author does not formulate the problem of the inducement to invest in modern terminology, and the ambiguities and contradictions in her exposition have left ample scope for her critics to represent her theory as irredeemable nonsense.[31] But the most natural way to read it is also the clearest. Investment can take place in an ever-accumulating stock of capital only if the capitalists are assured of an ever-expanding market for the goods which the capital will produce. On this reading, the statement of the problem leads straightforwardly to the solution propounded in the third Section of this book. Marx has his own answer to the problem of inducement to invest, which she refers to in the first chapter.[32] The pressure of competition forces each individual capitalist to increase his capital in order to take advantage of economies of large-scale production, for if he does not his rivals will, and he will be undersold. Rosa Luxemburg does not discuss whether this mechanism provides an adequate drive to keep accumulation going, but looks for some prospective demand outside the circle of production. Here the numerical examples, as she shows, fail to help. And this is in the nature of the case, for (in modern jargon) the examples deal with _ex post_ quantities, while she is looking for _ex ante_ prospects of increased demand for commodities. If accumulation does take place, demand will absorb output, as the model shows, but what is it that makes accumulation take place?