Essays in microeconomic theory

The thesis first provides an axiomatic characterization of the probability-weighted minimal norm solution for Bayesian social choice problems with reference points. Chapter 2 provides a characterization of feasibility conditions for general social choice problems. The examples include voting, auctions with externalities, package auctions and exchanges with complementary objects. Chapter 3 examines the existence of ex post efficient and monotone solutions for a two-person bargaining problem. Chapters 4 and 5 investigate two specific problems of designing trading mechanisms with monetary transfers to achieve certain welfare objectives