One of the troubles for many people about the discussion of the so-called ‘operation of the law of value in a socialist economy’ has been the question of terminology. This chapter deals with the proposals of Leonid Kantorovitch about prices and their relation. The use of modern mathematical methods in the organisation and planning of production provides a real and very efficient method of improvement. Kantorovitch says: ‘In applying a system of optimal planning a plan actually in operation over a number of years will inevitably not be optimal since changes in the situation and new data require continual changes of plan, and therefore the planned solutions already operating are frequently not optimal’—and as examples of new data he instances ‘appearance of new requirements; appearance of new products, replacing old ones; the appearance of new and improved techniques’.