Under central planning neither planners, managers, nor workers had incentives to promote the social economic interest. Nor did impeding markets for final goods to the planning system enfranchise consumers in meaningful ways. But central planning would have been incompatible with economic democracy even if it had overcome its information and incentive liabilities. And the truth is that it survived as long as it did only because it was propped up by unprecedented totalitarian political power.
Robin Hahnel, The ABC's of Political Economy, (2002) London: Pluto Press. p. 262.
A fully planned economy was based on the government deciding the priorities for production. Government ministries then issued production quotas, which factories strove to fulfill. The allocation of raw materials, energy, and workers was decided centrally, based on calculations of how much was needed to achieve the quotas on time. Transport, repairs, or new machinery were requested by the individual factory and decided on, according to political priority, by state institutions allocated such tasks. Investment and output were imagined to be in perfect balance, and resources therefore utilized to the utmost. Distribution replaced the market as a mechanism of dividing the output. No factories ever closed, and no workers were laid off. There was therefore full employment at all times. The country was a socialist economic machine, the purpose of which was to maximize production. Reality, of course, diverged rather substantially from this economic ideal, as did capitalist practices from free market thinking in nonsocialist countries. Although much was achieved in terms of increasing production during the first decades of full economic planning, mainly in industry (socialist agriculture always lagged behind), growth slowed later. Some of this is undoubtedly explained by the first phase of growth being pushed forward simply by unrealized potential from earlier decades. The resource advantages of centralization in an underdeveloped economy played a part in initial successes, as did the enthusiasm of workers to rebuild and see their factories and countries succeed. But there were also inefficiencies built into the planned economy, which became more glaring as economies matured. There was a lack of efficient allocation, innovation, and product differentiation. There was also a lack of incentives for workers, and a lack of economizing or preservation of resources, natural or industrial.
Odd Arne Westad, The Cold War: A World History (2017)