How to interpret an IRF function with exogenous covariates.
Example: Small open economy which I control for foreign variables (Endogenous variables cannot influence the exogenous variables). The endogenous variables included are Uncertainty index, interest rate, inflation, investment and GDP. The exogenous variables are the world interest rate and world GDP.
I perform a structuralized VAR with the aid of cholesky decomposition in order to perform an IRF function. The ordering follows; Uncertainty index, interest rate, inflation, investment and last GDP. If I look at an impulse-response function to a shock from uncertainty on the endogenous variables. Lets say one standard deviation shock. How will the exogenous variables work then? Will it effect the system at the same time as the uncertainty shock? Or have they already "influenced" by the exogenous variables before we shock the uncertainty variable? Is the effect Contemporaneous?
Impulse-response function is not my strong suit.
Best regards, Johan