The use of the pricing mechanism is central to any discussion of economic planning. Contrary to what was sometimes suggested in the 1940s economic planning did not mark the supplanting of the pricing mechanism, but rather a movement to a different set of prices. As Ely Devons informed the Nuffield conference on controls in June 1948, ‘the suggestion that when you operate through controls you are not operating though the price mechanism [is] … a great fallacy. The idea that controls allocate in terms of real resources is quite wrong. The people who control are in fact paying attention to prices. No one could operate a control system unless there were prices. But they are having regard to the entirely wrong set of prices.’

Discussions of pricing share some common ground with our previous concern with centralisation and decentralisation, many critics of socialist planning, notably von Mises in the 1920s and Hayek in the 1930s, accusing central planners of underestimating the ability of a decentralised structure of market prices to produce accurate and complex flows of information.