On the 16th of March 2020, the Polish Central Bank announced its first-ever round of Quantitative Easing. I am conducting an event study on how this announcement impacted the term structure.
The main obstacle is the fact that in the same press announcement the central bank also lowered its policy rate by 50 bps. My goal is to get an estimate of the reduction in the 10Y bond yield that would follow ONLY from the policy rate cut, based on the historical data. I have considered estimating the following equation:
\begin{align*} \Delta10Y\_Yield_{t}=\beta_{0}+\beta_{1}\Delta Policy\_Rate_{t}+\beta_{2}\Delta Policy\_Rate_{t}^{2}+u_{t} \end{align*}
What could be an alternative approach? Are you aware of any relevant literature?