"In horizontal mergers, concentration is often measured with the Hirschman-Herfindahl Index (HHI). This index yields the price-cost margins in Cournot competition. In many modern merger cases, both buyers and sellers have market power, and indeed, the buyers and sellers may be the same set of...

This article studies how players allocate their endowed resources between productive and conflictual activities in the context of rivalry between two groups. We show that the suboptimality and exploitation propositions established by Olson (1965) do not necessarily apply when external threat is...