This option provides the same behaviour as before the change in
60ef6bbdbd.
It is typically useful when doing several estimations in the same .mod file.
Incidentally, the auxiliary endogenous variable representing Z₁ and created for
PAC MCE models no longer necessarily appear as the first auxiliary variable (so
this is effectively a revert of 64f55e4a5e).
— forbid leads and lags
— forbid expectation operators
This is implemented by moving the occbin_constraints expression to a separate
DataTree. As a side-effect, this removes the spurious non-linearity warning in
a stochastic context (because we were introducing inequalities and abs()
operators in the main DynamicModel tree).
Previously the first value was silently ignored. It’s better to explicitly
forbid this. If this change creates problems (since it’s a change in an
undocumented behaviour), we can turn it into a warning.
In particular, this implies that steady state values of endogenous in the
“occbin_constraints” block must now be specified using the STEADY_STATE()
operator (and not with a “_ss” suffix).
Moreover:
– make various simplifications to the fields generated under M_
– in the driver file, replace the call to occbin.initialize() by a few explicit operations
Ref. #68
Consequently drop “occbin” option to “model”.
Incidentally, allow more values in equation tag names (previously some keywords
such as “alpha” were disallowed).
Ref. #68
As the name implies, this option allows contemporaneous variables on the RHS.
The A0 matrix for contemporaneous variables is added as a second (optional)
output to the generated var_ar.m file. Note that for reduced-form VAR, this
matrix will be the identity.
Also, the user is now allowed to write the VAR models in a more flexible form:
the LHS must still be a single variable, but the RHS can be an arbitrary
expression (as long as it is linear, obviously). Internally, the preprocessor
now uses derivation to compute the coefficients of the AR and A0. This change
applies to both reduced-form and structural VAR models.
Ref. dynare#1785
For the time being, the preprocessor will refuse that this option be used with
any command other than estimation.
By the way, remove occbin_likelihood and occbin_smoother options to estimation.
Ref. dynare#569