Stationarity problem in log-linarized model

Stochastic simulations
1

Hello guys, I am working with a DSGE model with Financial Accelerator. Although the rank condition is verified and I am taking impulse responses, those responses do not come back to steady state. It is saying that “All endogenous are constant or non stationary, not displaying correlations and auto-correlations”. I have 5 transitory shocks in the system and the shocks hit the economy separately. What should I do the get rid of this problem?

2

This most probably means there is a bug in your model and you accidentally introduced a unit root.

3

Hi all and Jpfeifer,

Could you please help me. I am replicating the Canova and Ravn (2000) RBC model. I have got the stochastic simulation and impulse responses. However, I do not get Theoretical Moments and Var Decomposition.

THEORETICAL MOMENTS
VARIABLE MEAN STD. DEV. VARIANCE
Ns_ss NaN NaN NaN
Nu_ss NaN NaN NaN
gam_ss NaN NaN NaN
ws_ss NaN NaN NaN
wu_ss NaN NaN NaN
r_ss NaN NaN NaN
y_ss NaN NaN NaN
he_ss NaN NaN NaN
hu_ss 1.0000 0.0000 0.0000
cu_ss NaN NaN NaN
yu_ss NaN NaN NaN
hs_ss NaN NaN NaN
cs_ss NaN NaN NaN
ysa_ss NaN NaN NaN
c_ss NaN NaN NaN
ks_ss NaN NaN NaN
k_ss NaN NaN NaN
xs_ss NaN NaN NaN
x_ss NaN NaN NaN
g_ss NaN NaN NaN

VARIANCE DECOMPOSITION (in percent)
epsilon_thetam epsilon_zeta
hu_ss 85.29 14.71

All endogenous are constant or non-stationary, not displaying correlations and auto-correlations

Could you give some advice, please? I do not understand how to fix the problem. I believe the problem is in the AR(1) process, I mean the shock in migration, but I am not able to see what is exactly the problem and how to fix it. You will have attached the mod and steady state files.
Many thanks!

Mig_5mar.mod (3.5 KB)
Mig_5mar_steadystate.m (3.7 KB)

4

model_diagnostics says

MODEL_DIAGNOSTICS:  The Jacobian of the static model is singular
MODEL_DIAGNOSTICS:  there is 1 colinear relationships between the variables and the equations
Colinear variables:
N     
Ns    
Nu    
No    
Colinear equations
     8     9    10    11    14    17    18    23

so you should find out what is going on there. Check all equations, including the timing. For example,
ks(-1) = Ns*((1 - delt)*ks(-1) + xs)/Ns(1);
looks wrong.

5

Thank you Profr Jpfeifer,

I have fixed the singularity of the model. Many thanks for your reply.

Best,
Aida