The capitalist system is far removed from the model of a competitive economy as elaborated by economic theory. And even if it conformed to it, it wou… - Oskar Lange

In my essay I refuted the Hayek-Robbins argument by showing how a market mechanism could be established in a socialist economy which would lead to the solution of the simultaneous equations by means of an empirical procedure of trial and error. [...] Were I to rewrite my essay today my task would be much simpler. My answer to Hayek and Robbins would be: so what’s the trouble?
Let us put the simultaneous equations on an electronic computer and we shall obtain the solution in less than a second. The market process with its cumbersome tatonnements appears old-fashioned. Indeed, it may be considered as a computing device of the preelectronic age.

It seems to us, indeed, that the real danger of socialism is that of a bureaucratization of economic life, and not the impossibility of coping with the problem of allocation of resources. Unfortunately, we do not see how the same, or even greater, danger can be averted under monopolistic capitalism. Officials subject to democratic control seem preferable to private corporation executives who practically are responsible to nobody.

I have pointed out that the real source of the superiority of Marxian economics is in the field of explaining and anticipating a process of economic evolution. It is not the specific economic concepts used by Marx, but the definite specification of the institutional framework in which the economic process goes on in capitalist society that makes it possible to establish a theory of economic evolution different from mere historical description. Most orthodox Marxists, however, believe that their superiority in understanding the evolution of Capitalism is due to the economic concepts with which Marx worked, i.e. to his using the labour theory of value. They think that the abandonment of the classical labour theory of value in favour of the theory of marginal utility is responsible for the failure of "bourgeois" economics to explain the fundamental phenomena of capitalist evolution. That they are wrong can be easily shown by considering the economic meaning of the labour theory of value. It is nothing but a static theory of general economic equilibrium. In an individualistic exchange economy, based on division of labour, in which there is no central authority to direct which commodities, and in what quantities, are to be produced, the problem is solved automatically by the fact that competition enforces such a distribution of productive resources between the various industries that prices are proportional to the amount of labour necessary for producing the respective commodities (these being the "natural prices" of classical economics).