The comparative analysis of socialist and capitalist economic systems has given rise to a voluminous literature, yet detailed analysis of the market socialism model, which seeks to imitate the functional efficiency of capitalism by simulating a competitive economy, has been relatively neglected. In this work, Mateusz Machaj seeks to redress this imbalance by providing an in-depth examination of a defining issue that separates capitalism from socialism – the system of ownership, or property rights – which, when explored, highlights fundamental problems in the market socialism model. Taking a broadly Austrian perspective, he shows that the mechanism of efficiency in market socialism is unable to play the part ascribed to it by its theoreticians, because it disregards that property rights are fundamental to the shaping of prices and thus the abolition of ownership in market socialism makes its mechanism of efficiency a fiction. The book offers new and original insights into the theory of competition, theories of pricing, property laws, the relation between law and economics, as well as the economics of the market socialism model.