Transmission protection drives 80 percent of ECB policy events
A Banque de France study identifies transmission protection as an active policy dimension in over 80 percent of ECB meetings since 2010. High-frequency asset price movements across 231 announcements show that anti-fragmentation measures operate independently from policy rate decisions.
Five dimensions in intraday volatility
Analyzing 16 financial series across 231 ECB announcements between May 2002 and January 2024, researchers Christoph Grosse-Steffen, Daniel J. Lewis, and Stéphane Lhuissier decompose market surprises into five dimensions: policy rate, forward guidance, asset purchases, transmission protection, and central bank information.
While conventional models impose time-invariant restrictions, this methodology exploits intraday heteroskedasticity in minute-by-minute asset price changes.
The findings show that transmission protection shocks explain up to 30 percent of 10-year risk-free rate variation and 25 percent of equity moves when active, compressing sovereign spreads and lowering redenomination risk.
From SMP to whatever it takes
The narrative decomposition tracks major historical milestones, from the Securities Markets Programme in 2010 to Mario Draghi’s 2012 “whatever it takes” speech and the 2022 Transmission Protection Instrument.
Intraday volatility spikes precisely match timestamped statements during press conferences.
Furthermore, the paper demonstrates that failing to account for transmission protection contaminates other surprise measures, showing a -0.31 correlation with standard central bank information shocks.
A glaring blind spot exposed
Standard event studies routinely misread policy shocks by ignoring central bank market backstops.
Proving that transmission protection directly moves risk-free yields exposes a glaring flaw in existing factor models.
Empirical research that overlooks anti-fragmentation measures will continue to miscalculate monetary policy effects.