Can we state that at a given Benassy Fixprice Allocation z " there is, say, excess effective demand for a commodity? It turns out that in productive economies there may be ambiguities in the sign of excess effective demand: different effective demand vectors with different signs. may be compatible with z*. We prove: (a) no ambiguity exists if intermediate goods are ruled out and if all firms in the long side of a market perceive binding constraints; (b) in any case one can always select a vector of effective demands yielding minimal sets of buyer's and seller's markets. 1.

Let F be a private ownership economy. Call an allocation w for a price vector p if no agent can benefit by trading less at p. We prove that, under differentiability and interiority, if w is voluntary and Pareto efficient it is a competitive equilibrium for W. Perhaps surprisingly, production economies where some agents receive profit income require a stronger voluntariness condition than the one sufficient for exchange economies. The stronger condition singles out a commodity as a medium of exchange.

[Arrow and Hahn's book General Competitive Analysis offers (Section 6.4) an existence theorem for non-competitive general equilibrium. Their formulation is apparently very general, but it becomes seriously restrictive in the presence of increasing returns to scale. An alternative existence theorem is presented here that obviates these shortcomings.]

The fall of Communism, the reassessment of Nordic social democracy, belt-tightening in other advanced welfare states, and the worldwide privatization wave have led many to conclude that egalitarianism is a merely utopian ideal, the possibility of whose realization is laid to rest by the failure of a series of twentieth-century social experiments. We survey the evidence, both empirical and theoretical, and conclude that obituaries are premature. Key theoretical errors in the design of egalitarian experiments, and in some critiques of pro-egalitarian policies, concern the role of information asymmetries, and we argue that their proper understanding re-opens possibilities for increasing equality without unacceptable sacrifices in efficiency.