In the book, Lange advocated the use of market tools (especially the neoclassical pricing theory) in economic planning of socialism and Marxism. He proposed that central planning boards set prices through "trial and error", making adjustments as shortages and surpluses occur rather than relying on a free price mechanism. Under this system, central planners would arbitrarily pick a price for products manufactured in government factories and raise it or reduce, depending on whether it resulted in shortages or gluts. After this economic experiment had been run a few times, mathematical methods would be employed to plan the economy: if there were shortages, prices would be raised; if there were surpluses, prices would be lowered. Raising the prices would encourage businesses to increase production, driven by their desire to increase profits, and in doing so eliminate the shortage. Lowering the prices would encourage businesses to curtail production in order to prevent losses, which would eliminate the surplus. In Lange's opinion, such simulation of market mechanism would be capable of effectively managing supply and demand. Proponents of this idea argued that it combines the advantages of a market economy with those of socialist economy.