# Corporate Income Tax

## Changes to the FRB/US model

- Corporate income tax accruals and related variables are consolidated in the new model across government categories.

Old model

    tfcin - tfcin_aerr = trfci*ynicpn

    tscin - tscin_aerr = trsci*ynicpn

New model

    tcin - tcin_aerr = trci*ynicpn

- The structure of the average S&L corporate income tax rate (TRSCI) was somewhat retained, although simplified and streamlined, for the consolidated equation of TRCI.

Old model

    trsci - trsci_aerr =
    y_trsci(1)*trsci(-1)
     + y_trsci(2)* trscit
     + y_trsci(3)* trscit(-1)
     + y_trsci(4)* xgap2
     + y_trsci(5)* xgap2(-1)
     + y_trsci(6)*d(trfci)

New model

    trci - trci_aerr = trcit
     + y_trci(1)*(trci(-1) - trcit(-1))
     + y_trci(2)*xgap2

- As a result, a trend counterpart to TRCI is created, TRCIT, which is assumed to be exogenous.