中文摘要
为探讨不良政策以民粹主义极端主义这一形式的传播,我们构建了一个以代理问题为特征的社会学习模型。不同国家的政治家相继实施某项政策。选民除了观察本国政策之外,还通过观察外国政策来获知在任政治家的类型以及合意的政策。我们证明,民粹主义极端主义通过不断变化的公众舆论与已实施政策之间的动态互动在国家间传染。这一结构产生了有趣的长期动态。第一,单个温和政策可能总是足以阻止多米诺效应。第二,多米诺效应的持续性取决于合意政策在国家间的相关性。具体而言,在完全相关情形下极端主义终将结束,而在不完全相关情形下,逃离极端主义可能变得不可能。这些结果揭示了分权式政策制定的一个新的负面面向。
Abstract
To explore the propagation of undesirable policies in a form of populist extremism, we construct a social learning model featuring agency problems. Politicians in different countries sequentially implement a policy. Voters learn the incumbent politician’s type and the desirable policy by observing foreign policies on top of the domestic policy. We show that populist extremism is contagious across countries through the dynamic interaction between the changing public opinion and implemented policies. This structure yields interesting long-run dynamics. First, a single moderate policy could be always enough to stop the domino effect. Second, the persistence of the domino effect depends on the correlation of the desirable policy across countries. In particular, while extremism eventually ends under the perfect correlation, it may become impossible to escape from extremism under the imperfect correlation. These results illuminate a new negative aspect of decentralized policymaking.