Dear Professor Pfeifer，

I have been learning Dynare for some time and I encountered a few questions when writing the dynare code. Would you please help me out ? Any reply will be appreciated, thank you !

(1) It’s a question about the form of shock equation. In a non-linear model, when the code is written like “exp(var)” form, the shock equation is written as:

“exp(A_e) = 1 - rho_A_e * 1 + rho_A_e * exp(A_e(-1)) + e_A_e”,

but if the code is written like “var” form(without “exp” ), Does the shock equation should be written as:

“A_e = 1 - rho_A_e * 1 + rho_A_e * A_e(-1) + e_A_e” ?

(2) It’s also a question about shock equation. In a non-linear model, when the code is written like “var” form, Is there any chance that the shock equation is written as:

“log(A_e) = rho_A_e * log (A_e(-1)) + e_A_e” ?

(3) It’s a question about Bayesian estimation. Is there a normal range of the " initial value of the log posterior(or likelihood)" so that I could tell whether the code is right or not from the beginning of the estimation ?

Any reply will be appreciated, thanks again !