When would an oligopolistic entrant imitate an incumbent’s product (“me-too” entry), rather than horizontally differentiate? We allow an entrant's product choice to vary endogenously with the cost of product differentiation. Such endogenity of product differentiation significantly affects the comparison of Bertrand and Cournot duopoly. We find that if Bertrand entry occurs, products are differentiated, whereas there is a substantial region in which Cournot entry involves a homogenous product. Bertrand prices may be higher than Cournot prices; and, if product differentiation costs are low enough to induce Cournot differentiated entry, then Bertrand industry profit equals or exceeds Cournot industry profit.

寡头垄断的进入者何时会模仿在位者的产品（“me-too”进入），而不是横向区分？我们允许进入者的产品选择随着产品差异化的成本而内生变化。这种产品差异化的内生性显着影响了 Bertrand 和 Cournot 双头垄断的比较。我们发现，如果发生 Bertrand 进入，产品就会出现差异化，而在相当大的区域内，Cournot 进入涉及同质产品。贝特朗价格可能高于古诺价格；并且，如果产品差异化成本低到足以引起古诺差异化进入，那么伯特兰行业利润等于或超过古诺行业利润。