at the end of the preceding taxable year (other than those assets which are used directly in carrying out the institution’s exempt purpose) is at least $250,000 per student of the institution. (2) Students For purposes of paragraph (1), the number of students of an institution shall be based on the daily average number of full-time students attending such institution (with part-time students taken into account on a full-time student equivalent basis). (c) Net investment income For purposes of this section, net investment income shall be determined under rules similar to the rules of section 4940(c). (d) Assets and net investment income of related organizations (1) In general For purposes of subsections (b)(1)(C) and (c), the assets and net investment income of any related organization shall be treated as the assets and net investment income of the eligible educational institution. (2) Related organization For purposes of this subsection, the term related organization means, with respect to an eligible educational institution, any organization which— (A) controls, or is controlled by, such institution, (B) is controlled by one or more persons that control such institution, or (C) is a supported organization (as defined in section 509(f)(3)), or an organization described in section 509(a)(3), during the taxable year with respect to such institution. . (b) Clerical amendment The table of subchapters for chapter 42 is amended by adding at the end the following new item: Subchapter H—Excise tax based on investment income of private colleges and universities . (c) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2017. 5104. Exception from private foundation excess business holding tax for independently-operated philanthropic business holdings (a) In general Section 4943 is amended by adding at the end the following new subsection: (g) Exception for certain holdings limited to independently-operated philanthropic business (1) In general Subsection (a) shall