Recently, I came across this article, which offers a simple model for estimating the probabilities of interest rate cut/hike from a central bank. This is done by using market data, especially normal market rates and forward rates. Unfortunately, this paper's two most important equations (3.2 and 3.3) have confusing and inconsistent notation and I have not managed to replicate the example in it. My goal is to do something like the Fed's market probability tracker. Unfortunately, the papers the Fed provided are way too complicated for my purposes.
My question is - are there any papers out there estimating this? Preferably the model should be as simple as possible. Any scripts (R/Python/Matlab) that do this would also be appreciated.
Thanks for help!