In Lieu of an Introduction: How I Remember Leonid Hurwicz -- Institution Design: Technical Change and the Decentralization Penalty -- Fundamental Theory of Institutions: a Lecture in Honor of Leo Hurwicz -- The Hurwicz Program, Past and Suggestions for the Future -- Social Networks from a Designer's Viewpoint -- Design Under Uncertainties: Some Remarks on Bayesian Mechanism Design -- Feasible Nash Implementation of Social Choice Rules When the Designer Does Not Know Endowments -- Design of Tradable Permit Programs Under Imprecise Measurement -- Second Thoughts of Social Dilemma in Mechanism Design -- Markets: Allocation Mechanisms, Incentives, and Endemic Institutional Externalities -- The Role of (quasi) Analyticity in Establishing Completeness of Financial Markets Equilibria -- Are We There Yet? Mechanism Design Beyond Equilibrium -- Rules: Formation of Committees Through Random Voting Rules -- Equal Area Rule to Adjudicate Conflicting Claims -- Implementation: Recent Results on Implementation with Complete Information -- Unrestricted Domain Extensions of Dominant Strategy Implementable Allocation Functions -- Self-Implementation of Social Choice Correspondences in Strong Equilibrium -- New Directions in Design: Domains Admitting ex post Incentive Compatible and Respectful Mechanisms: a Characterization for the Two Alternatives Case -- Mechanisms in a Digitalized World -- Incentive Compatibility on the Blockchain -- Contextual Mechanism Design. .

This book contains invited essays in memory of Leonid Hurwicz spanning a large area of economic, social and other sciences where the implementation or enforcement of institutions and rules requires the design of effective mechanisms. The foundations of these articles are set by social choice concepts; game theory; Nash, Bayesian and Walrasian equilibria; complete and incomplete information. Besides in-depth treatments of well-established parts of mechanism and implementation theory, contributions on novel directions deal, for instance, with a quantum approach to game and decision making under uncertainty; digitalization; and the design of block chain for trading. The outstanding competence and reputation of the authors reflect the appreciation of the fundamental contributions and the lasting admiration of the personality and the work of Leonid Hurwicz.