The thesis provides a philosophically grounded account of a socialist planned economy. While I do not primarily consider a positive case for socialism, I address two major objections to it and thus argue that the possibility of socialism as an alternative form of economic organisation has been dismissed too quickly. Furthermore, I provide an account of the precise form a socialist economy should take, outlining general principles of planning and distribution. Based on a welfarist interpretation of Marx, I show that (...) distribution of consumer goods should be facilitated by an equal distribution of tokens. These tokens can be redeemed for consumer products or substituted for additional leisure time. The rates at which tokens can be redeemed for consumer products should correspond to market clearing prices. Welfare-oriented socialism is also defended against a deontological objection to socialism by Robert Nozick, who claims that socialism leads to injustice because it violates private property rights. The thesis also considers Ludwig von Mises’s calculation argument against socialism, which claims that socialism leads to the abolition of economic rationality. I show how this objection can be overcome by using optimal planning techniques which are responsive to consumer demand as signalled by the market clearing rates of consumer products. The resulting model of socialism is tested using a computer simulation. The simulation also demonstrates that a novel system of valuation based on opportunity cost leads to a better adaptation of production in response to environmental constraints when compared to the labour values of classical political economy. (shrink)