“…This paper is related to three strands of the literature. Firstly, several papers have studied how a common shock to marginal costs affects firms' profits and social welfare in an asymmetric Cournot oligopoly with fixed number of firms (for example: Seade, 1985, Kimmel, 1992, Anderson et al, 2001, Février and Linnemer, 2004, Reny at al., 2012, Amir et al, 2016,, Häckner and Herznig, 2016. A result of this literature is that such a shock can be profitable for high-cost firms vis-à-vis low-cost firms.…”