Uygulanabilirlik ve tekdüzelik üzerine çalışmalar

In this thesis we study the implementation problem with regard to the relationbetween monotonicity and implementability. Recent work in the eld hasshown that the implementability of a social choice rule strongly depends uponthe compatibility between the monotonicity structures of the social choice ruleand of the solution concept according to which implementation takes place.Dierent degrees of monotonicity of the social choice rules and game theoreticsolution concepts can be determined via a generalized monotonicity function,strongest of which is called self-monotonicity. In this study, we determinethe unique self-monotonicity of the Nash equilibrium concept and show thatthe monotonicities of a social choice rule are inherited from the unique selfmonotonicityof the Nash equilibrium concept via the mechanisms that implementit. In particular, we show that the essential monotonicity is inherited viathe Maskin-Vind type mechanism which is widely used in the characterizationresults. We also give a new characterization of strong Nash implementablesocial choice rules via critical proles. We show that coalitional monotonicitywhen conjoined with three more conditions is both necessary and sucientfor implementability. Finally we determine a subset of subgame perfect Nashimplementable social choice rules that satises conditions dened obtained bycritical proles. The results that are obtained in this thesis strongly supportthe view that implementation theory can be rewritten in terms of monotonicityand that this provides a better understanding of the theory.