Part I. The surveys: Axioms for social welfare orderings/ Claude d'Aspremont -- Solutions to the bargaining problem/ Ehud Kalai-- Theories of justice based on symmetry/ William Thomson and Hal R. Varian -- Strategy-proofness : the existence of dominant strategy mechanisms/ Eitan Muller and Mark A. Satterthwaite -- Theory of implementation in Nash equilibrium : a survey/ Eric S. Maskin -- Implementation via Nash equilibria in economic environments/ Andrew Postlewaite -- Bayesian equilibrium and incentive-compatibility : an introduction/ Roger B. Myerson -- Economics of competitive bidding : a selective survey/ Paul R. Milgrom. -- Part II. Six Papers by Elisha A. Pazner: Difficulty in the concept of fairness (with David Schmeidler) -- Recent thinking on economic justice -- Social contract theory and ordinal distributive equity (with David Schmeidler) -- Pitfalls in the theory of fairness -- Cheatproofness properties of the plurality rule in large societies (with Eugene Wesley) -- Egalitarian equivalent allocation : a new concept of economic equity (with David Schmeidler).