Connectedness of economic policy uncertainty and oil price shocks in a time domain perspective

In this paper, we investigate causality and connectedness between economic policy uncertainty and oil price shocks across time scales. By incorporating the wavelet approach into the structural vector autoregression (VAR) framework proposed by Diebold and Yilmaz (2009, 2012, 2014), we find that crude oil prices behave like receivers of information from economic policy uncertainty, regardless of time scale. However, the causality relationship between economic policy uncertainty and oil price shocks intensifies as time scales increase. In addition, the connectedness relationship is robust to time scale changes, whereas the causal relationship intensifies as time scales increase. Notably, the weight of US economic policy uncertainty increases in the VAR system as time scales increase. In particular, we employ the West Texas Intermediate (WTI) crude oil price as an alternative measure to increase the robustness of our results and identify differences in the VAR system. Overall, the total connectedness of the WTI crude oil price is lower than that of the Brent crude oil price, regardless of time scale. Our results provide meaningful information for both investors and policymakers.