account which gave rise to the reserve for deferred taxes. Under such method, if timing differences for the property reverse, the amount of the adjustment to the reserve for the deferred taxes is calculated by multiplying— (i) the ratio of the aggregate deferred taxes for the property to the aggregate timing differences for the property as of the beginning of the period in question, by (ii) the amount of the timing differences which reverse during such period. (C) Alternative method The alternative method is the method in which the taxpayer— (i) computes the excess tax reserve on all public utility property included in the plant account on the basis of the weighted average life or composite rate used to compute depreciation for regulatory purposes, and (ii) reduces the excess tax reserve ratably over the remaining regulatory life of the property. (4) Tax increased for normalization violation If, for any taxable year ending after the date of the enactment of this Act, the taxpayer does not use a normalization method of accounting, the taxpayer’s tax for the taxable year shall be increased by the amount by which it reduces its excess tax reserve more rapidly than permitted under a normalization method of accounting. B Cost recovery 3101. Increased expensing (a) 100 percent expensing Section 168(k)(1)(A) is amended by striking 50 percent and inserting 100 percent . (b) Extension through January 1, 2023 Section 168(k)(2) is amended— (1) in subparagraph (A)(iii), by striking January 1, 2020 and inserting January 1, 2023 , (2) in subparagraph (B)(i)(II), by striking January 1, 2021 and inserting January 1, 2024 , (3) in subparagraph (B)(i)(III), by striking January 1, 2020 and inserting January 1, 2023 , (4) in subparagraph (B)(ii), by striking January 1, 2020 in each place it appears and inserting January 1, 2023 , and (5) in subparagraph (E)(i), by striking January 1, 2020 and replacing it with January 1, 2023 . (c) Application to used property (1) In general Section 168(k)(2)(A)(ii) is amended to read as follows: