We consider a stable improvement problem in a controlled school choice model which covers those of several previous studies. First, we consider the case where the priority for each school is a weak order. We derive a sufficient condition for a stable matching to be constrained efficient. It is...

This study considers a hybrid voting model where some of the voters sincerely vote but the others may not. By using the model, we discuss several voting rules: the random dictatorship rule, plurality rule, Borda rule and others. In each rule, we derive the threshold such that a Pareto efficient...

This study analyzes the number of matches in stable and efficient matchings. The benchmark number of matches is the largest one among the matchings in which no agent can be better off by itself. We show that, in the one-to-one matching model, the number of matches in any stable matching is more...

This study considers a voting rule wherein each player sincerely votes when he/she has no information about the preferences of the other players. We introduce the concept of rank-dominant strategies to discuss the situation where a player is completely ignorant and decision theoretic...

In this paper, we consider a market where potential firms, which are allowed to be asymmetric, can freely enter and exit, and the total output would be socially excessive without any regulation. The effects of two alternative regulatory policies in the market: the individually transferable quota...

In priority-based two-sided matchings, a respecting-improvements property of a mechanism requires that an agent should get weakly better off when she is assigned a higher priority. Not only is it a normative desideratum, it is also important for ex-ante investments and for disclosure of...

We consider a controlled school choice model where students are divided into several types such as socioeconomically advantaged and disadvantaged. The priority for a school is dependent on the type distribution of the assignment. Our model is a generalization of several models in previous...