Ever since Lange’s influential essay (1936–37) on market socialism, explicit discussions of the concept have revolved to a large extent around the Langian model. Bergson’s two survey articles on the subject are illustrative of this tendency (1948, 1967), as are many textbook treatments (Halm, 1960, pp. 159–218; Kohler, 1966, pp. 68–82; Ward, 1970, pp. 14–42). More recently, considerable discussion has been generated in the literature on the cooperative firm model (Domar, 1966; Sen, 1966; Oi and Clayton, 1968), which is essentially a market socialist concept as well. Finally we may cite Ames’ application of the output-maximizing model in a Soviet socialist context (1965). Although the Soviet economy is generally accepted to be more planning than market oriented, Ames’ “first approximation to reality” in the description of the representative Soviet firm is clearly equivalent to output-maximization subject to a no-loss constraint under perfect competition. All three of these models of market socialism are of considerable intrinsic interest, and well merit the detailed attention they have received in the literature. Nevertheless, it will be argued here that none of these three models represents the most natural, obvious, logical and plausible conception of “market socialism,” and that exclusive preoccupation with these models hampers a thorough appreciation and examination of the basic, fundamental and essential issues involved in the evaluation of the potential efficiency of market socialism.