Are log-linearization and calculation of Hessian matrix involved in this DSGE model

Dear Johannes,
Thank you very much your previous help, I am grateful.
I am following this paper ‘Risk Shocks’(Attachment
CMR.pdf (1.2 MB)
) to develop new DSGE models for my research question, however, I think it is a nonlinear DSGE model right? Does estimation for any nonlinear DSGE model involve log-linearization and calculation of Hessian matrix to identify parameters?
Thank you very much and look forward to hearing from you.
Best regards,
Jesse

You are confusing things. The CMR model is a nonlinear model solved linearly. You could also estimate nonlinear models e.g. using particle filters or GMM. The Hessian at the mode is only computed to generate a proposal density for the MCMC, but that is not a necessary step. Pretty much any positive definite matrix should work. But this has nothing to do with identification.