Rational herd behavior and informationally efficient security prices have long been considered to be mutually exclusive but for exceptional cases. In this paper we describe conditions on the underlying information structure that are necessary and sufficient for informational herding. Employing a...

This paper focuses on the coalitional approach to sequential trading processes. We study the allocation of resources through sequential trading, when individuals have the option to form coalitions and make group decisions. We introduce a new core concept, called the two stage core, which is...