We study a major new entry in the French mobile telecommunications market, followed by the introduction of fighting brands by the three incumbents. Using an empirical oligopoly model, we find that the incumbents’ fighting brand strategies are difficult to rationalize as unilateral best responses. Instead, their strategies are consistent with a breakdown of tacit semi-collusion: before entry, the incumbents could successfully coordinate on restricting product variety to avoid cannibalization; after entry, this outcome became harder to sustain because of increased business stealing incentives. Consumers gained considerably from the added variety and, to a lesser extent, from the incumbents’ price responses. (JEL L13, L21, L96, M31)

中文翻译：

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市场准入、品牌斗争和默契合谋：来自法国移动电信市场的证据

我们研究了法国移动电信市场的一个重要新进入，然后是三个老牌企业引入的战斗品牌。使用经验寡头垄断模型，我们发现现有企业的品牌竞争战略难以合理化为单方面的最佳反应。相反，他们的策略与默认的半合谋的破裂是一致的：在进入之前，在位者可以成功地协调限制产品种类以避免自相残杀；进入后，由于增加了商业窃取动机，这种结果变得更难维持。消费者从增加的品种中获益良多，在较小程度上从现有企业的价格反应中获益。(JEL L13, L21, L96, M31)