Our conclusion about the objectivity of economic science may seem startling. Economists are rather notorious for being unable to reach agreement and … - Oskar Lange

Our results may be summarised as follows:
(1) The superiority of Marxian economics in analysing Capitalism is not due to the economic concepts used by Marx (the labour theory of value), but to the exact specification of the institutional datum distinguishing Capitalism from the concept of an exchange economy in general.
(2) The specification of this institutional datum allows of the establishment of a theory of economic evolution from which a "necessary" trend of certain data in the capitalist system can be deduced.
(3) Jointly with the theory of historical materialism this theory of economic evolution accounts for the actual changes occurring in the capitalist system and forms a basis for anticipating the future.

Having treated the theoretical determination of economic equilibrium in a socialist society, let us see how equilibrium can be determined by a method of trial and error similar to that in a competitive market. This method of trial and error is based on the parametric function of prices. Let the Central Planning Board start with a given set of prices chosen at random. All decision of the managers of production and of the productive resources in public ownership and also all decisions of individuals as consumers and as suppliers of labour are made on the basis of these prices. As a result of these decisions the quantity demanded and supplied of each commodity is determined. If the quantity demanded of a commodity is not equal to the quantity supplied the price of that commodity has to be changed. It has to be raised if demand exceeds supply and lowered if the reverse is the case. Thus the Central Planning Board fixes a new set of prices which serves as a basis for new decisions, and which results in a new set of quantities demanded and supplied. Through this process of trial and error equilibrium prices are finally determined. Actually the process of trial and error would, of course, proceed on the basis of the prices historically given. Relatively small adjustments of those prices would constantly be made, and there would be no necessity of building up an entirely new price system.

Capitalism operates only on the basis of private costs, only private costs are rewarded and repaid, and not social costs. And even in a competitive capitalism where competition forces producers to sell at cost price takes into account only private costs and not social costs.