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α: calibrated so average coauthorship-adjusted count equals average raw count
We examine oligopoly models of vertical product differentiation in which producing firms face variable costs of quality development. We show that comparing to private oligopoly, mixed oligopoly – whereby state-owned enterprises (SOEs) and private firms coexist – enhances social welfare but reduces firms' profitability. We also demonstrate that Bertrand competition makes firms better off under mixed oligopoly but it makes firms worse off under private oligopoly compared with Cournot competition. These findings help to justify both the existence of SOEs and the efficiency of SOEs and private firms in mixed markets in transitional economies.