Multiple randomised field experiments confirm that door-to-door canvassing and live telephone calls are effective methods of moving voters to the polls, but they require significant investments of time and resources and are difficult to bring to scale. In contrast, methods such as email, text messaging, or messages posted on social media networks are less resourceintensive and are easily expanded to large numbers of target voters. In this paper, we test the effectiveness of short candidate videos sent to eligible voters using the popular smartphone application WhatsApp. Using a set of randomised field experiments conducted during the 2014 elections in Brazil, we make two contributions to the literature. First, we find that short videos delivered via WhatsApp are a powerful method of increasing turnout among teen voters, confirming our hypothesis about how today’s teens think about the networked publics in which they participate. Second, we add Brazil to the list of countries in which the traditional method of door-to-door canvassing has been proven a powerful method of mobilising voters.

中文翻译：

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巴西的WhatsApp：通过门到门和个人信息动员选民

多个随机的野外实验证实，挨家挨户的拉票和现场电话是使选民参加投票的有效方法，但它们需要大量的时间和资源投入，并且难以扩大规模。相反，诸如电子邮件，文本消息或在社交媒体网络上发布的消息之类的方法资源消耗较少，并且很容易扩展为大量目标选民。在本文中，我们测试了使用流行的智能手机应用程序WhatsApp发送给符合条件的选民的简短候选视频的有效性。我们使用2014年巴西大选期间进行的一组随机现场实验，对文献做出了两点贡献。首先，我们发现通过WhatsApp播放的简短视频是增加青少年选民投票率的有效方法，证实了我们关于当今青少年如何看待他们所参与的网络公众的假设。第二，我们将巴西加入到传统的门到门拉票方法被证明是动员选民的有力方法的国家列表中。