to the regulatory authority of that jurisdiction. (3) Definitions For purposes of this subsection— (A) Excess tax reserve The term excess tax reserve means the excess of— (i) the reserve for deferred taxes (as described in section 168(i)(9)(A)(ii) of the Internal Revenue Code of 1986) as determined under the Internal Revenue Code of 1986 as in effect on the day before the date of the enactment of this Act, over (ii) the amount which would be the balance in such reserve if the amount of such reserve were determined by assuming that the corporate rate reductions provided in this Act were in effect for all prior periods. (B) Average rate assumption method The average rate assumption method is the method under which the excess in the reserve for deferred taxes is reduced over the remaining lives of the property as used in its regulated books of 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