Dynare forums

Hello everybody,

for computing higher-order approximations and being able to use the error function in the model equations I wanted to try Dynare++. Playing aroung with the simple RBC model in its plain vanilla type (CRRA utility function with consumption and labor, Cobb-Douglas production function, TFP shock, no frictions) I was not able to get the results of Dynare++ and Dynare in accordance. The model is approximated to the 2ed order. The following counter-intuitive results occured:

- Dynare++ produces means for consumption, investment, capital and production that are below their deterministic steady states. Dynare does the opposite. As it is not allowed to upload .mat files I just give the mean values for the capital stock:
Dynare: 11.4907; Dynare++ 11.3885; deterministic steady state: 11.4297.

- Adding a second shock variable (Variable "b") in Dynare++ that does not occur in any other model equation changes the results of Dynare++ for all variables, e.g. mean capital stock: 11.5538.

I do not unterstand these results.

The model files for both Dynare (PlainVanilla.mod) and Dynare++ (PlainVanilla++.mod, PlainVanillaB++.mod) are enclosed. I suppose that I make a simple general mistake in Dynare++ that I just don't see. It would be very helpful if you could help me out.

Many thanks,

Peter

Hi,

I've checked your files and in my case the two models (plain and B) produce the same mean in Dynare++ (4.1.0)

I confirm though that there is a discrepancy between Dynare and Dynare++ (even using the same file, renamed and fixed).

I wonder whether they (both) return theoretical moments. If not, this could be a reason.

Best

Gianni