论文标题
随机共识和怀疑的阴影
Stochastic Consensus and the Shadow of Doubt
论文作者
论文摘要
我们提出了网络中意见交流的随机模型。在固定网络结构中组织了有限的代理。世界上有二进制状态,每个代理商在该州都会收到一个私人信号。我们将信念建模为红球代表状态的一个可能值,而蓝色球则是另一个值。该模型纯粹围绕沟通和信念动态。沟通发生在离散的时间,在每个时期,代理商通过更换从urn中绘制并显示一个球。然后,他们通过添加邻居抽出的颜色的球来加强他们的ur。我们表明,对于任何网络结构,此过程几乎将其收敛到稳定状态。 futher,我们表明,如果连接通信网络,则这种稳定的状态使得所有urn都具有相同的球。这一结果增强了非拜尔斯学习模型的主要收敛特性。然而,与这些模型相反,我们表明此极限比例是一个全供支持的随机变量。这意味着,任意的较小的错误信息代理可以实质性地改变极限共识的价值。我们提出了一组基于模拟的限制比例分布的猜想。特别是,我们表明了极限信念遵循Beta分布,其平均值与网络结构无关。
We propose a stochastic model of opinion exchange in networks. A finite set of agents is organized in a fixed network structure. There is a binary state of the world and each agent receives a private signal on the state. We model beliefs as urns where red balls represent one possible value of the state and blue balls the other value. The model revolves purely around communication and beliefs dynamics. Communication happens in discrete time and, at each period, agents draw and display one ball from their urn with replacement. Then, they reinforce their urns by adding balls of the colors drawn by their neighbors. We show that for any network structure, this process converges almost-surely to a stable state. Futher, we show that if the communication network is connected, this stable state is such that all urns have the same proportion of balls. This result strengthens the main convergence properties of non-Bayesian learning models. Yet, contrary to those models, we show that this limit proportion is a full-support random variable. This implies that an arbitrarily small proportion of misinformed agents can substantially change the value of the limit consensus. We propose a set of conjectures on the distribution of this limit proportion based on simulations. In particular, we show evidence that the limit belief follows a beta distribution and that its average value is independent from the network structure.