(dissenting, with whom Hennessey, C.J., joins). My views remain unchanged on the subject of the relationship between the requirement of art. 44 of the Amendments to the Constitution of the Commonwealth that an income tax be levied at a uniform rate on income derived from the same class of property and the Legislature’s right under art. 44 to grant “reasonable exemptions” from income taxation. In Opinions of the Justices, 386 Mass. 1223 (1982), I concluded that a taxation bill not meaningfully different from the statute now before us (G. L. c. 62, § 3 [b], as appearing in St. 1985, c. 593, § 6) was constitutionally competent. The court’s opinion in this case describes differences between the bill the Justices considered in 1982 and the act now before us and, without saying how or why, characterizes these differences as “significant” (ante at 44). The differences have no substantial significance warranting a change of opinion concerning the application of art. 44 principles.1
There is in art. 44 an inherent and unavoidable conflict between the mandate of uniform rates and the authorization of reasonable exemptions. Opinions of the Justices, supra at 1226. *49Any exemption destroys uniformity. Reasonable exemptions, however, do not destroy the uniformity that art. 44 requires. The court’s opinion in this case, however, improperly gives near conclusive effect to the requirement of uniform rates, thus relegating the right to grant reasonable exemptions to insignificance.
I would have thought that this court, following its own precedents, would have expressed deference to the Legislature’s judgment as to what exemptions were reasonable in these circumstances. When the Justices furnish an advisory opinion, there is no presumption of the validity of a proposed statute. Opinion of the Justices, 345 Mass. 780, 781-782 (1963). Where, however, this court addresses “a constitutional challenge to a tax measure, we begin with the premise that the tax is endowed with a presumption of validity and is not to be found void unless its invalidity is established beyond a rational doubt.” Andover Sav. Bank v. Commissioner of Revenue, 387 Mass. 229, 235 (1982), and cases cited. The court’s opinion acknowledges that, in past decisions, we have upheld a flat exemption based on ability to pay. The use of decreasing exemptions, scaling down from a flat exemption which would itself be proper under art. 44, injects a greater element of fairness than would a flat exemption standing alone. In addition, the difference in the effective tax rate due to the exemptions is minor.2 This is hardly a graduated income tax of the sort that art. 44 plainly forbids. The Legislature’s judgment that a minor exemption should be apportioned according to each taxpayer’s ability to pay falls in the range of reasonableness within which the Legislature is entitled to act.
The greater number of classifications in the act over the number in the 1982 bill tends to reduce the problem of disproportionate additional income tax that results when a taxpayer earns just enough income so as to move into the lower range of a higher bracket. See Opinions of the Justices, supra at 1229-1230. The exemption completely disappeared in the 1982 bill, but it does not in the new G. L. c. 62, § 3 (b).
Considering, for example, the earned income of a single taxpayer (and disregarding any surtax), the person in the highest income tax bracket pays $160 more in income tax (5% of $3,800 less $600) than he would have had to pay without the decreasing exemption.