研究期間：10108~10207;We will compare mixed duopoly with pure duopoly in a setting where there are two firms producing differentiated goods. We study quantity competition as well as price competition. The demands arise from a representative consumer whose utility function is quasi-linear. It is allowed that there exists demand or cost asymmetry between the two firms. Moreover, we will not restrict the degree of asymmetry such that there may exist a corner equilibrium in mixed duopoly. We will use reaction curves to conduct the analysis. Moreover, we will use the following five reference points: Stackelberg equilibrium, socially first-best outcome, a fully collusive outcome, a socially second-best outcome and a privately second-best outcome. In order to highlight an important tradeoff, we will emphasize the distinction between output level and output structure.