Corporate income tax (at least for publicly traded corporations) should be a straight 20% (down from 35%) of the yearly profit from the corporation's annual report, the SEC approved, and audited report they show to Wall St investors. No allowances for domestic production, use of ethanol, purchase of electrical vehicles, green goodness or anything else. No loss carryover, loosing money last year is no reason to get a tax break this year.
Rationale. Accounting is so slippery that clever and crooked accountants can and do turn losses into profits, loans into income, phone bills into capital investments, and similar trickery that we might as well take advantage of all the rules and paperwork that attempts to limit accounting swindles for tax assessment. Plus companies are less likely to declare purely imaginary profits when they have to pay taxes on them.