gcubed.constants

The version of the G-Cubed Python implementation.

The build of the G-Cubed Python implementation.

The delta used to compute numeric derivatives when linearising the model. This delta matches the value used in the Ox implementation of G-Cubed.

The delta used to compute the Jacobian related to the intertemporal constants.

Note that a considerably larger value of DELTA is used when calculating the partial derivatives of the initial projection values of the variables whose values are adjusted by the intertemporal constants because those variable values are linear functions of the intertemporal constants. The size of the delta does not matter, theoretically, when calculating the partial derivatives of linear systems and a larger value of DELTA is used to eliminate precision issues. In the Ox implementation of G-Cubed, the DELTA used was 0.00001 but this can be made even larger to achieve better precision of the derivative estimates.

The ROGY (potential output growth rate) variable prefix.

The INFP (inflation rate in PRID) variable prefix.

The INFX (inflation rate target) variable prefix.

The PRID (weighted price of domestic output) variable prefix.

The REXC variable prefix.

The wage variable prefix.

The nominal GDP variable prefix.

The real GDP variable prefix, LGDPR.

The GDPR variable prefix.

The GDPN variable prefix.

The TRAN variable prefix (transfers to households).

The ratio of nominal local GDP to nominal GDP of the reference country (typically the USA), both measured in the currency of the reference country. These variables are used to convert variables expressed as a percentage of local GDP to a percentage of reference country GDP. They are also used in the calibration of the ashr parameters describing international financial asset holdings by each region.

The real interest rate variable prefix.

The nominal interest rate variable prefix.

The real interest rate variable prefixes.

These are the prefixes of the variables that are set equal to the neutral real interest rate (set in the model configuration, ModelConfiguration.neutral_real_interest_rate) when doing linearisation of the model and when determining the adjustments to make to equate projections to observed data when doing the baseline projections.

• INTF is the real short-run interest rate.
• INTR is the 'risk-adjusted' real short-run interest rate, controlled by the central bank, equal to INTF plus RISR - an exogenous risk-premium in the yield curve. Note that RISR is typically zero in the databases and would be used to run simulation experiments.

The nominal interest rate variable prefixes.

These are the prefixes of the variables that are set equal to the neutral real interest rate plus the expected inflation rate when doing linearisation of the model and when determining the adjustments to make to equate projections to observed data when doing the baseline projections.

• INTN is the nominal short-run interest rate, controlled by the central bank.

The lagged nominal interest rate variable prefixes.

These are the prefixes of the variables that are set equal to the neutral real interest rate plus the expected inflation rate when doing linearisation of the model and when determining the adjustments to make to equate projections to observed data when doing the baseline projections.

Note that with the removal of INTL, there are no longer any of these variables in G-Cubed models from build 181 onwards.

The long bond rate (real and nominal) variable prefixes.

The state vector lead (stl variable types in SYM) variable prefixes.

The units of GDP that indicate that the variable values are divided by the nominal GDP of the reference country, expressed in local currency units for the reference country (USD if the USA is the reference country).

The units of GDP that indicate that the variable values are divided by local nominal GDP, expressed in the local currency of the reference country.

These units are of interest because we can multiply by ratio of local GDP to reference country GDP to convert the variable so that it is instead divided by reference country GDP.