component member is a corporation described in section 535(c)(2)(B)) amount for purposes of computing the accumulated earnings credit under section 535(c)(2) and (3). Such amount shall be divided equally among the component members of such group on such December 31 unless the Secretary prescribes regulations permitting an unequal allocation of such amount. (b) Certain short taxable years If a corporation has a short taxable year which does not include a December 31 and is a component member of a controlled group of corporations with respect to such taxable year, then for purposes of this subtitle, the amount to be used in computing the accumulated earnings credit under section 535(c)(2) and (3) of such corporation for such taxable year shall be the amount specified in subsection (a) with respect to such group, divided by the number of corporations which are component members of such group on the last day of such taxable year. For purposes of the preceding sentence, section 1563(b) shall be applied as if such last day were substituted for December 31. . (B) The table of sections for part II of subchapter B of chapter 5 is amended by striking the item relating to section 1561 and inserting the following new item: Sec. 1561. Limitation on accumulated earnings credit in the case of certain controlled corporations. . (7) Section 7518(g)(6)(A) is amended— (A) by striking With respect to the portion and inserting In the case of a taxpayer other than a corporation, with respect to the portion , and (B) by striking (34 percent in the case of a corporation) . (c) Reduction in dividend received deductions to reflect lower corporate income tax rates (1) Dividends received by corporations (A) In general Section 243(a)(1) is amended by striking 70 percent and inserting 50 percent . (B) Dividends from 20-percent owned corporations Section 243(c)(1) is amended— (i) by striking 80 percent and inserting 65 percent , and (ii) by striking 70 percent and inserting 50 percent . (C) Conforming amendment The heading for section 243(c)