We study stable school formation among four students that differ in ability and income. In the presence of ability complementarities and school costs to be shared, we identify the conditions under which a stable allocation is efficient, inefficient, nonexistent, and tell who become peers.

This article proposes a simple Nash program. Both our axiomatic characterization and our noncooperative procedure consider each distinct asymmetric and symmetric Nash solution. Our noncooperative procedure is a generalization of the simplest known sequential Nash demand game analyzed by ...