”Why is it that capitalists end up getting the better part of the deal – that is, they end up with the surplus, and the worker ends up with his wage, which in the Marxian view was only enough for him to subsist upon? The answer lies not in the fact that the capitalist is more clever or has the police on his side: it is that capital is scarce relative to the available supply of labor, and workers must bid for the right to use that scarce capital, which provides them with a wage. Were labor scarce, then capital would have to bid for labor, and profits would be bid down to a minimal level, at which capitalists were indifferent between continuing to own capital and becoming workers. Why capitalism seems to have been characterized, throughout its history, as a situation of capital scarcity is not fully understood. Marx argued that capitalists as a class, perhaps represented by the state, undertook strategies to guarantee a ‘reserve army of the unemployed,’ in order to maintain the imbalance. Indeed, the proletarianization of the agricultural periphery is an important process by which labor abundance has been maintained until the present (see Rosa Luxemburg). Keynes and Schumpeter envisaged a time when capital would cease to be scarce, bringing about the euthanasia of the capitalist class.John E. Roemer, professor i statsvetenskap och nationalekonomi vid Yale University, "Socialism: A Modern Perspective", i The New Palgrave Dictionary of Economics, 2008 (artikeln finns här).
Thus, the fundamental source of the accumulation of wealth in the hands of a small class, through profits created in production, is that abundant workers must bid for the ‘privilege’ of using their labor power on privately owned productive assets that increase its productivity immensely. This provides them with a wage greater than they could have earned in the non-capitalist sector (back on the family farm, so to speak, or selling apples from a street cart), and also produces an additional amount that, according to the labor-capitalist bargain, belongs to the capitalist. Capitalists consume a part of this surplus product, and invest the rest in other profit-making activities.”