On January 8, 2026, Romain Crucil will publicly defend his thesis entitled:

"Monetary Policy and Uncertainty: The Higher-Order Nexus" 

at 9:00 at HEC Liège, Classroom 0/86 (N1d Building)

Please confirm your presence to romain.crucil@uliege.be

Jury members 

• Prof. Julien Hambuckers, Supervisor, HEC Liège
• Prof. Simone Maxand, Europa-Universität Viadrina
• Prof. Pierrick Clerc, HEC Liège
• Prof. Georges Hübner, President of the Jury, HEC Liège
• Dr. Thomas Lejeune, National Bank of Belgium (NBB)
• Rafael Wouters, National Bank of Belgium (NBB)

Summary

In a global environment marked by profound structural changes, the past two decades have brought successive shocks that have reshaped both the conduct and the understanding of monetary policy. Prolonged periods of exceptionally low interest rates compelled central banks to expand their toolkit beyond conventional instruments, while the subsequent surge in inflation across advanced economies prompted a rapid tightening of policy stances. These innovations have contributed, among other developments, to heightening the sensitivity of financial markets to policy signals and to underscoring the challenges inherent in navigating an increasingly uncertain macro-financial landscape.

Set against this evolving and uncertain macro-financial landscape, the central theme of this thesis emerges: the higher-order nexus linking monetary Policy and the deeper forms of uncertainty surrounding the structure of the economy. This nexus encompasses both the uncertainty that policy decisions generate in financial markets and the uncertainty policymakers themselves face about how the structural representation of the economy. Focusing on the Euro Area, the first chapter of the dissertation establishes that financial uncertainty cannot be treated as fully exogenous; rather, it is partly endogenous to monetary policy, with important consequences for business-cycle fluctuations. The second chapter further demonstrates that the effects of policy on uncertainty vary across financial markets and depend on the specific instruments and dimensions of policy interventions, reflecting the increasingly multifaceted nature of modern monetary frameworks. Finally, the last chapter investigates how policymakers can design monetary policy rules that remain robust when the structural representation of the economy is itself uncertain, particularly in settings where financial frictions and modern macroeconomic models add complexity to policy design.

The thesis also advances the quantitative analysis of these mechanisms, combining advanced empirical tools with new methodological contributions for measuring uncertainty, identifying monetary policy effects, and evaluating robust policy rules under model uncertainty.

Taken together, these contributions clarify the higher-order nexus connecting monetary policy and uncertainty, improving our understanding of how this relationship shapes macro-financial dynamics.