Economic Policy Uncertainty (EPU) represents the uncertainty realized by the investors during economic policy alterations. EPU is a critical indicator in economic studies to predict future investments, the unemployment rate, and recessions. EPU values can be estimated based on financial parameters directly or implied uncertainty indirectly using the text mining methods. Although EPU is a well-studied topic within the economy, the methods utilized to measure it are understudied. In this article, we define the EPU briefly and review the methods used to measure the EPU, and survey the areas influenced by the changes in EPU level. We divide the EPU measurement methods into three major groups with respect to their input data. Examples of each group of methods are enlisted, and the pros and cons of the groups are discussed. Among the EPU measures, text mining-based ones are dominantly studied. These methods measure the realized uncertainty by taking into account the uncertainty represented in the news and publicly available sources of financial information. Finally, we survey the research areas that rely on measuring the EPU index with the hope that studying the impacts of uncertainty would attract further attention of researchers from various research fields. In addition, we propose a list of future research approaches focusing on measuring EPU using textual material.

翻译：经济政策不确定性（EPU）指投资者在经济政策调整过程中感知到的不确定性。EPU是经济研究中预测未来投资、失业率及经济衰退的关键指标。EPU值可直接基于金融参数估算，亦可运用文本挖掘方法间接反映隐含不确定性。尽管EPU在经济领域已得到充分研究，但其测量方法仍相对不足。本文简要定义EPU，系统梳理现有EPU测量方法，并考察受EPU水平变化影响的领域。我们根据输入数据类型将EPU测量方法划分为三大类，列举各类方法的典型案例并探讨其优缺点。在现有EPU测量方法中，基于文本挖掘的方法占据主导地位。此类方法通过分析新闻及公开金融信息来源中隐含的不确定性，实现对已实现不确定性的量化。最后，我们系统梳理依赖EPU指数测量的研究领域，以期不确定性影响研究能吸引更多领域学者的关注。此外，我们提出未来重点利用文本材料测量EPU的研究方向。