IRIS Toolbox Reference Manual

!log_variables

List of log-linearised variables

Syntax

!log_variables
    Variable_Name, Variable_Name, 
    Variable_Name, ...

Syntax with inverted list

!log_variables
    !all_but
    Variable_Name, Variable_Name, 
    Variable_Name, ...

Syntax with regular expression(s)

!log_variables
    Variable_Name, Variable_Name, 
    Variable_Name, ...
    <REGEXP>, <REGEXP>, ...

Description

List all log-variables under this headings. Only measurement or transition variables can be declared as log-variables.

In non-linear models, all variables are linearised around the steady state or a balanced-growth path. If you wish to log-linearise some of them instead, put them on a !log_variables list. You can also use the !all_but keyword to indicate an inverse list: all variables will be log-linearised except those listed.

To create the list of log-variables, you can also use regular expressions, each enlosed in a pair of angle brackets, < and >. All measurement and transition variables whose names match one of the regular expressions will be declared as log-variables. See also help on regular expressions in the Matlab documentation.

Example

The following block of code will cause the variables Y, C, I, and K to be declared as log-variables, and hence log-linearised in the model solution, while r and pie will be linearised:

!transition_variables
    Y, C, I, K, r, pie

!log_variables
    Y, C, I, K

You can do the same job by writing

!transition_variables
    Y, C, I, K, r, pie

!log_variables
    !all_but
    r, pie

Example

We again achieve the same result as above, but now using a regular expression.

!transition_variables
    Y, C, I, K, r, pie

!log_variables
    <[A-Z]\w*>

The regular expression [A-Z]\w* selects all variables whose names start with an upper-case letter. Hence, again the variables Y, C, I, and K will be declared as log-variables.