This paper develops a multi-country model of international trade that provides a simple micro-foundation for buyer-seller relationships in trade. We explore a rich dataset that identifies buyers and sellers in trade and establish a set of basic facts that guide the development of the theoretical model. We use predictions of the model to examine the role of buyer heterogeneity in a market for fi...

We extend to bimodules Schelter’s localization of a ring with respect to Gabriel filters of left and right ideals. Our two-sided localization of bimodules provides an endofunctor on a convenient bicategory of rings with filters of ideals. This is used to study the Picard group of a ring relative to a filter of ideals.

We show that previous filtering propositions on two-sided stability problems do not enforce arc consistency (AC), however they maintain Bound(D) Consistency (BC(D)). We propose an optimal algorithm achieving BC(D) with O(L) time complexity where L is the length of the preference lists. We also show an adaptation of this filtering approach to achieve AC. Next, we report the first polynomial time...