concurring in part and dissenting in part. I concur in Parts I
and III of the majority opinion. As to Part II, however, I dissent. This court has traditionally upheld the test-year concept. Part I of the majority opinion, Consumers’ Counsel v. Pub. Util. Comm. (1981), 67 Ohio St. 2d 372 [21 O.O.3d 234], and Ohio Water Service Co. v. Pub. Util. Comm. (1983), 3 Ohio St. 3d 1, enhance that tradition. Nevertheless, the majority fails to recognize that the issue in Part II is essentially the same as that in Part I: whether this court will reverse the decision of the Public Utilities Commission to exclude a post-test-year expense from consideration. Both Consumers’ Counsel, supra, and Ohio Water Service, supra, lead to the same conclusion. We should affirm the decision of the Public Utilities Commission *107because: (1) the requested expense was incurred after the test year, and (2) the utility decided when to file its rate case. See Consumers’ Counsel, supra, at pages 374-376.
We should not apply or construe R.C. 4909.161. Nothing in that provision suggests that it was intended to supersede the test-year concept. Furthermore, its application may violate the constitutional prohibition against the retroactive application of statutes, see Section 28, Article II of the Ohio Constitution, and the statutory presumption in favor of prospective laws, see R.C. 1.48, because R.C. 4909.161 became effective after the original tax liability accrued and after the test year.
Accordingly, I would affirm the decision of the Public Utilities Commission as to all three issues before this court.