When Less Is More: Experimental Evidence on Information Delivery During India’s Demonetisation
Review of Economic Studies · 2023 · Abhijit Banerjee、Emily Breza、Arun G. Chandrasekhar、Benjamin Golub
中文摘要
在传播信息时，政策制定者面临一个选择：向所有人广播信息，还是告知少数“种子”人物、再由其传播消息。尽管广播能够最大化信息的初始覆盖范围，但我们提供的理论与实验证据表明，广播未必是最佳策略。在2016年印度废钞令期间开展的一项田野实验中，我们传递了政策信息，并在村庄层面改变了传递方式的三个维度：初始覆盖范围（广播还是种子传播）；是否促成了关于“最初哪些人获知信息”的共同知识；以及所传递事实的数量。我们衡量了三个结果：关于废钞令的谈话量、对废钞令规则的了解程度，以及在一项强激励且依赖政策的决策中的选择质量。在全部三个结果上，在存在共同知识的条件下，种子传播均优于广播；此外，增加共同知识会使种子传播更有效，却会使广播的效果更差。我们通过一个“形象顾虑阻碍社会学习参与”的模型来解释这些结果，并以不同能力类别之间行为差异的证据支持这一解释。
Abstract
Abstract In disseminating information, policymakers face a choice between broadcasting to everyone and informing a small number of “seeds” who then spread the message. While broadcasting maximises the initial reach of messages, we offer theoretical and experimental evidence that it need not be the best strategy. In a field experiment during the 2016 Indian demonetisation, we delivered policy information, varying three dimensions of the delivery method at the village level: initial reach (broadcasting versus seeding); whether or not we induced common knowledge of who was initially informed; and number of facts delivered. We measured three outcomes: the volume of conversations about demonetisation, knowledge of demonetisation rules, and choice quality in a strongly incentivised policy-dependent decision. On all three outcomes, under common knowledge, seeding dominates broadcasting; moreover, adding common knowledge makes seeding more effective but broadcasting less so. We interpret our results via a model of image concerns deterring engagement in social learning, and we support this interpretation with evidence on differential behaviour across ability categories.