The purpose of this paper is to investigate the impact of heterogeneous beliefs about market demand on the profitability of firms under different competitive settings. To this end I consider a differentiated duopoly model where two firms with different beliefs about the market demand can compete in quantity (Cournot competition) or in price (Bertrand competition). The results show that the optimistic firm can outperform the pessimistic firm in profits under Cournot competition even in the state of Low demand as long as the ratio of High demand over Low demand is sufficiently low. Under Bertrand competition, however, if the ratio of High demand over Low demand is sufficiently low or the overall optimism of the two firms is sufficiently high, the pessimistic firm can gain higher profit than the optimistic one even when demand is high.

中文翻译：

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具有异质信念的差异化双头垄断中的价格和数量竞争

本文的目的是调查关于市场需求的不同观念对不同竞争环境下企业盈利能力的影响。为此，我考虑了一种差异化的双头垄断模型，其中对市场需求有不同信念的两家公司可以在数量（古诺竞争）或价格（贝特朗竞争）中竞争。结果表明，只要在高需求与低需求之比足够低的情况下，即使在低需求状态下，乐观公司在古诺竞争下的利润也能超过悲观公司。但是，在Bertrand竞争下，如果高需求与低需求之比足够低，或者两家公司的总体乐观度足够高，那么即使需求很高，悲观企业也可以获得比乐观企业更高的利润。