arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1009.2653cs.SIcs.SYeess.SYmath.OCmath.PR
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社交网络中的意见波动与分歧

Opinion fluctuations and disagreement in social networks

Massachusetts Institute of Technology(麻省理工学院);Lund University(隆德大学);Politecnico di Torino(都灵理工大学)

Daron Acemoglu, Giacomo Como, Fabio Fagnani, Asuman Ozdaglar

AI总结:

本文研究了一个易处理的意见动力学模型,该模型通过包含固执代理人的非齐次随机八卦过程,解释了长期分歧和持续意见波动,并证明了在高度流动的大规模社会中会出现同质影响现象。

摘要:

我们研究了一个易处理的意见动力学模型,该模型产生长期分歧和持续的意见波动。我们的模型涉及一个非齐次随机八卦过程,用于连续意见动力学,社会由两类代理人组成:常规代理人,他们根据从社交邻居那里收到的信息更新自己的信念;以及固执代理人,他们从不更新自己的意见。当社会包含持有不同意见的固执代理人时,信念动态永远不会导致(常规代理人之间的)共识。相反,社会中的信念几乎必然不收敛,信念分布以遍历方式持续波动,并在分布上收敛到一个非退化的随机向量。网络结构以及固执代理人在其中的位置塑造了意见动态。期望信念向量根据一个常微分方程演化,该方程与具有吸收状态(对应于固执代理人)的连续时间马尔可夫链的柯尔莫哥洛夫后向方程一致,并收敛到一个调和向量,其中每个常规代理人的值是其邻居值的加权平均,边界条件对应于固执代理人。代理人信念的期望交叉积允许在网络上耦合马尔可夫链方面进行类似的刻画。我们证明,在高度流动的大规模社会中,即描述社交网络的图上的马尔可夫链的混合时间与固执代理人链接的相对大小的乘积随着人口规模增长而消失时,会出现一种“同质影响”条件,即大多数常规代理人的平稳信念边际分布具有近似相等的一阶和二阶矩。

英文摘要:

We study a tractable opinion dynamics model that generates long-run disagreements and persistent opinion fluctuations. Our model involves an inhomogeneous stochastic gossip process of continuous opinion dynamics in a society consisting of two types of agents: regular agents, who update their beliefs according to information that they receive from their social neighbors; and stubborn agents, who never update their opinions. When the society contains stubborn agents with different opinions, the belief dynamics never lead to a consensus (among the regular agents). Instead, beliefs in the society fail to converge almost surely, the belief profile keeps on fluctuating in an ergodic fashion, and it converges in law to a non-degenerate random vector. The structure of the network and the location of the stubborn agents within it shape the opinion dynamics. The expected belief vector evolves according to an ordinary differential equation coinciding with the Kolmogorov backward equation of a continuous-time Markov chain with absorbing states corresponding to the stubborn agents and converges to a harmonic vector, with every regular agent's value being the weighted average of its neighbors' values, and boundary conditions corresponding to the stubborn agents'. Expected cross-products of the agents' beliefs allow for a similar characterization in terms of coupled Markov chains on the network. We prove that, in large-scale societies which are highly fluid, meaning that the product of the mixing time of the Markov chain on the graph describing the social network and the relative size of the linkages to stubborn agents vanishes as the population size grows large, a condition of \emph{homogeneous influence} emerges, whereby the stationary beliefs' marginal distributions of most of the regular agents have approximately equal first and second moments.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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