What is the test for equalization under the Income Tax Act?

It was said in Thibaudeau v. Canada, 1995 CanLII 99 (SCC), [1995] 2 S.C.R. 627, that it is of the very essence of the Income Tax Act to make distinctions so as to generate revenue for the government while equitably reconciling a range of necessarily divergent interests (pp. 676 and 702). Gonthier J. went on to say at p. 676: . . . In view of this, the right to the equal benefit of the law cannot mean that each taxpayer has an equal right to receive the same amounts, deductions or benefits, but merely a right to be equally governed by the law. . . . . . . one should not confuse the concept of fiscal equity, which is concerned with the best distribution of the tax burden in light of the need for revenue, the taxpayers' ability to pay and the economic and social policies of the government, with the concept of the right to equality, which as I shall explain in detail later means that a member of a group shall not be disadvantaged on account of an irrelevant personal characteristic shared by that group.