中文摘要
Gentzkow 和 Kamenica (2016) 证明,当且仅当信息环境是 Blackwell 连通的时,发送方之间的竞争才会使接收方受益。本文表明,引入接收方的有限注意与异质性信念可以推翻这一结论。即使在 Blackwell 连通的信息环境中,双寡头下的信息披露水平也可能低于垄断情形。事实上,有限注意可能促使接收方分流至观点相近发送方的受众群体。而这一不利的分流进而可能使发送方以披露更少的信息为最优。
Abstract
Gentzkow and Kamenica (2016) show that competition among senders benefits receivers if and only if the information environment is Blackwell-connected. This paper shows that introducing receivers’ limited attention and heterogeneous beliefs can overturn this result. Even in a Blackwell-connected information environment, information revelation may be lower under duopoly than under monopoly. Indeed, limited attention may incentivize receivers to sort into the audiences of like-minded senders. In turn, this adverse sorting can make it optimal for senders to reveal less information.