Uncertainty is acknowledged to be a source of economic fluctuations. But, does the type of uncertainty matter for the economy's response to an uncertainty shock? This article offers a novel identification strategy to disentangle different types of uncertainty. It uses machine learning techniques to classify different types of news instead of specifying a set of keywords. The article finds that, depending on its source, the effects of uncertainty on a macroeconomic variable may differ. I find that both good (expansionary effect) and bad (contractionary effect) types of uncertainty exist.

中文翻译：

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不确定因素

不确定性被认为是经济波动的根源。但是，不确定性的类型对经济对不确定性冲击的反应有影响吗？本文提供了一种新颖的识别策略，以消除不同类型的不确定性。它使用机器学习技术对不同类型的新闻进行分类，而不是指定一组关键字。该文章发现，不确定性取决于其来源，其对宏观经济变量的影响可能有所不同。我发现不确定性既有好的（扩展效应）也有不好的（收缩效应）类型。