The Impact of Heterogeneous Unconventional Monetary Policies on Market Uncertainty

This article analyzes the impact of the unconventional monetary policies (UMPs) of four major central banks (the Fed, ECB, BoE and BOJ) on market uncertainty. We exploit the heterogeneity of different UMP actions to disentangle their influence on reducing the ex ante perception of extreme events (tail risks) using the information contained in risk-neutral densities from the most liquid stock index options. The empirical findings show that the announcement of UMPs reduces the risk-neutral probability of extreme events across various horizons and thresholds, supporting the hypothesis of the risk-taking channel. The most effective measures are the forward guidance and liquidity actions, rather than asset purchases. Interestingly, foreign UMP actions also prove to be significant variables affecting domestic tail risks, mainly at longer horizons. These results reveal an original cross-border effect of foreign UMPs on domestic tail risks. Finally, the dynamics of the UMPs are captured by a structural model that confirms a transitory impact of UMPs on market tail risk perceptions.