Ill. Admin. Code tit. 83, § 556.50
b) The pre-tax return shall be calculated by using the following formulas:
PTR = ((WCCE + WCPE) x GRCF) + WCLTD + WCSTD
| GRCF | = | 1 |
| (1 – (PPTRIT+ SIT)) x (1 - FIT) |
Where:
| GRCF | = | Gross Revenue Conversion Factor. |
| PPTRIT | = | Illinois Personal Property Tax Replacement Income Tax rate in effect at the time of the filing. |
| SIT | = | Illinois State income tax rate in effect at the time of the filing. |
| FIT | = | Federal income tax rate in effect at the time of the filing. |
| PTR | = | Pre-tax return. |
| WCCE | = | Weighted cost of common equity approved in the utility's last rate case proceeding. |
| WCPE | = | Weighted cost of preferred equity approved in the utility's last rate case proceeding. |
| WCLTD | = | Weighted cost of long term debt and credit facilities fees approved in the utility's last rate case proceeding. |
| WCSTD | = | Weighted cost of short term debt approved in the utility's last rate case proceeding. |