The purpose of the paper is to provide a simple model explaining buyer-supplier relationships and show what factors determine the number of trading partners. We show that when the supplier is able to determine the number of trading partners, the optimal number is small if the supplier's...

This paper examines the questions of who participates in the provision of a public good through the voluntary participation of agents in the presence of strong complementarity between a public good and a private good. We show that the greater the initial endowment of the private good that agents...

We analyze firms' decisions to adopt a vertical integrated or decentralized structure taking into account the characteristics of both the final good competition and the R&D process. We consider two vertical chains, where R&D is conducted by upstream sectors. R&D investment determines the...

We provide a model in which upstream producers, whose production cost is quadratic in quantity, sell their products through two distribution channels, a traditional channel and an external retailer. Some producers (called "large" producers) supply to both channels, whereas other producers...