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steady

PostPosted: Mon Feb 06, 2006 10:47 am
by bamba
hi stephane,
trying to estimate a model, i compute the the variables at steady state( in file filename_steadystate.m), but i realise that the value computed is false ; dynare uses the initial values at the block initval or not .
Thanks

PostPosted: Mon Feb 06, 2006 12:26 pm
by StephaneAdjemian
Hi,

I'm not sure to understand your problem.

Dynare cannot use the block initval when estimating a model, because this block is not updated each time the values of the deep parameters are modified (during the optimization algorithm or the metropolis).

(...) but i realise that the value computed is false


What do you mean ? If you wrongly define the steady state, a false value is the right answer...

Best,
St

steady

PostPosted: Mon Feb 06, 2006 5:32 pm
by bamba
the steady state values computed are not the same ones i calculated

Re: steady

PostPosted: Mon Feb 06, 2006 6:28 pm
by StephaneAdjemian
bamba wrote: the steady state values computed are not the same ones i calculated


You should check your equations in the _steadystate.m file (it may be caused by a little typo). An easy way to check for this is to evaluate the static version of your model at what you think to be the steady state. You may proceed as follows :

(1) After the model block write an initval block using exactly the same formulas as in your _steadystate.m file.

(2) After the initval block use the following command resid(1);

(3) that's all you need.

Run the mod file. The command resid evaluates the static model at the point defined in the block initval, by printing on the matlab prompt a $(N+1) \times 1$ vector (where N is the number of equations in your model). If the point defined in the initval block is a fixed point the displayed vector should be null everywhere except in the first position. If the (i+1)-th scalar is non-zero you have a problem in equation i of your model. The problem may be a typo in the model declaration, a typo in the equations defining the steady state or an error in your algebra :cry:

Best, St