This study examines the time-frequency causal link between economic policy uncertainty and inflation in Japan while answering the following questions: (i) is there any causal link between economic policy uncertainty and inflation in Japan? (ii) if yes, in which direction(s)? To the best of our knowledge, this is the first study that conducts this nexus. To do so, this study employs the wavelet coherence causality test and focuses on the wide range period from 2003:03 to 2021:03, in which Japan was experienced the specific Quantitative and Qualitative Monetary Easing Policies. Overall, the findings mirror that economic policy uncertainty is an essential predictor of inflation in Japan, and economic policy uncertainty leads to inflation at different periods and frequencies. The results of this study are crucial for policy decision-making, monetary authorities, and central banks, and Japan should reduce uncertainty about economic policies to curb the possible risk of inflation rises. The policymakers in Japan can control the inflation rate fluctuation if they can ensure a more reliable prediction of economic policies.

中文翻译：

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经济政策不确定性和通货膨胀之间的时间和频率联动：来自日本的证据

本研究考察了日本经济政策不确定性和通货膨胀之间的时频因果关系，同时回答了以下问题：(i) 日本经济政策不确定性和通货膨胀之间是否存在任何因果关系？(ii) 如果是，在哪个方向？据我们所知，这是进行这种联系的第一项研究。为此，本研究采用小波相干因果关系检验，重点关注从 2003:03 到 2021:03 的广泛时期，日本在这段时期内经历了特定的量化和定性货币宽松政策。总体而言，研究结果表明，经济政策不确定性是日本通胀的重要预测指标，经济政策不确定性导致不同时期和频率的通胀。这项研究的结果对政策决策至关重要，货币当局、央行和日本应降低经济政策的不确定性，以遏制可能出现的通胀上升风险。如果日本的政策制定者能够确保对经济政策的预测更加可靠，那么他们就可以控制通货膨胀率的波动。