Hello,
I am currently working on the codes from Gali 2015 chapter _3.mod (the linear model). And I see that the coefficients of autocorrelation are all the same () why is that?
Because, there is most likely a single shock variable in the model.
To be more precise, the Gali model is purely forward-looking. There is no endogenous propagation via endogenous state variables. Hence, the endogenous variables all inherit the persistence from the exogenous shocks. As you only have a single shock, all variables are just a function of that shock and have exactly the same autocorrelation.