Perhaps I'll make some introductory comments, and then Mr. Trueman can talk a little bit more.
What this measure deals with is an additional deduction in excess of the small business deduction, which is available to Canadian-controlled private corporations.
The small business deduction is available on the first $500,000 of income for corporations whose taxable income is less than $10 million, and then it's phased out as taxable income increases up to $15 million.
Over time, when the additional deduction was first introduced, the structure of the small business deduction back in the 1970s was significantly different, and the limit on the small business deduction was actually based on cumulative taxable income. The policy concern that was being addressed in the 1970s, when the additional deduction was first introduced, was that because of the statutory requirements on credit unions that applied, it would prevent credit unions from replenishing their ability to access the small business deduction in a way that other corporations could do.
The small business deduction structure has changed significantly since the 1970s, so the same technical policy reason for the additional deduction is not the same. Now the ability to access the small business deduction is based on taxable capital as opposed to cumulative taxable income.
That's just some background on how the additional deduction came about.
I think I'll just pass it to Mr. Trueman. He can speak more specifically to your policy question.