¶ 15. {concurring). I agree with the result reached in the majority opinion and with much of its reasoning. I write separately to amplify why the dispute in this case is not simply over the fair market value of a particular piece of property on a given day. If it were, I would be hard pressed not to agree with the City's assertion that the choice between the two valuations is simply a question of fact, to be determined by the fact finder (here, the board of review), whose determination we should accept because it found the City's assessor more credible than the partnership's appraiser.
*795¶ 16. I recognize that, in the absence of a recent arms-length sale, property valuation depends largely on matters of judgment and expertise. I am also aware that appraised values of a particular property can differ sharply, and that it is most often the fact finder's proper role to assess the weight and credibility of competing opinions of fair market value. See, e.g., Schorer v. Schorer, 177 Wis. 2d 387, 396-97, 501 N.W.2d 916 (Ct. App. 1993). Here, however, the discrepancy in the opposing valuations boils down to the choice between two mortgage interest rates for inclusion in the capitalization rate — the subsidized rate of 1% or the actual or market rate of 8.5% — and, depending on which is chosen, the resulting valuation of the property will either be close to $500,000 or less than $200,000.
¶ 17. Mineral Point Valley's property is far from unique, in that it is by no means the only federally subsidized housing development in Wisconsin. This means that the choice between the two mortgage rates at issue here must be made by assessors throughout the state whenever the income approach is employed to determine the value of properties that are subject to the same types of benefits and restrictions as the one before us. Like my colleagues on this panel, I therefore conclude that the choice of which interest rate to plug into the valuation calculation is not the type of "fact" that can or should change from case to case, based solely on which party in an assessment dispute produces the more credible expert on a given day.
¶ 18. The supreme court addressed a similar technical valuation issue in Soo Line R.R. Co. v. DOR, 97 Wis. 2d 56, 59-60, 292 N.W.2d 869 (1980). The court there discussed what standard should be applied when an appellate court reviews a trial court's decision regarding a valuation derived from the application of an *796"abstract formula." Id. The supreme court affirmed this court's decision to set aside a trial court order which sustained the Department of Revenue (DOR)'s valuation of railroad property for property tax purposes. In doing so, the court rejected the DOR's argument that the valuation in question was a factual determination which could only be disturbed if contrary to the great weight and clear preponderance of the evidence. See id.
¶ 19. The court concluded that the determination at issue required "an examination of the formula that was used to arrive at the challenged valuation", which distinguished it from more typical trial court fact and credibility determinations, to which reviewing courts, for good reasons, defer. See id. at 60. The court explained:
If the question here at issue were more in the nature of the typical factual determination that trial courts are required to make, we would find this argument quite persuasive. Generally, factual determinations are made on the basis of the factfinder's observations of the witnesses as they relate their version of the events in question. Particularly where different witnesses give conflicting testimony, the factfinder's opportunity to observe the witnesses as they testify under oath and subject to cross-examination places him in a much better position to evaluate the truthfulness of their respective testimony. A witness' demeanor on the stand and the manner in which he answers questions are indications' of truthfulness which cannot he conveyed in a written record. It is primarily for this reason that appellate courts have traditionally accorded substantial weight to factual findings made at the trial level.
However, the question to be determined here has little to do with the credibility of witnesses, at least in the sense that phrase is generally used. The DOR's *797assessment of the Soo Line's operating property is the product of an abstract formula devised by DOR and applied to the facts or data which are themselves undisputed. In determining whether the DOR's assessment was substantially more or less than the actual fair market value of the Soo Line's property, the trial court was required to decide whether the application of that formula in this case produced a result which substantially reflected the full value of the railroad. This determination requires not so much an evaluation of the truthfulness of the witnesses, but rather an examination of the formula that was used to arrive at the challenged valuation. It requires an understanding and rational assessment of the mathematic and economic principles underlying the basic formula and the specific adjustments made by the DOR.
Id. at 59-60.
¶ 20. I am aware that this court previously rejected an attempt by an appellant, based on the analysis in Soo Line, to have this court apply a de novo standard in reviewing a trial court's choice between competing expert valuations of a business for purposes of a divorce. See Siker v. Siker, 225 Wis. 2d 522, 530-32, 593 N.W.2d 830 (Ct. App. 1999). We acknowledged in Siker that the competing evaluations in the divorce were arguably based on "abstract formulas", id. at 530, but we nonetheless distinguished Soo Line because, among other things, Soo Line involved a "statutorily prescribed judicial review of a taxing authority's property value assessment," id. at 531. We noted that the question before the courts in Soo Line involved whether the DOR's assessment method conformed "to state and federal laws and constitutions." Id. (citation omitted). We concluded that a de novo appellate determination of the proper valuation method might be appropriate where a court's role is "to ensure that a taxing authority had discharged its respon*798sibilities to the public at large, as well as to an individual taxpayer, in accordance with applicable law." Id. at 531-32. In other property value determinations, however, such as those made in divorce property divisions, the clearly erroneous standard of review for factual findings should be applied. Id.
¶ 21. I believe that the very rationale that served to distinguish Soo Line from Siker, supports our applying the Soo Line standard of review in this case. This, like Soo Line, is a statutorily prescribed judicial review of a taxing authority's property value assessment. Our function is not simply to ensure that the board of review made a reasonable call based on the testimony of competing experts, but also to ensure that it "discharged its responsibilities to the public at large, as well as to an individual taxpayer, in accordance with applicable law." Id. As in Soo Line, I conclude that, with respect to the present dispute over which mortgage interest rate to employ in valuing federally subsidized housing for tax assessment purposes, "an appellate court need not accord special deference to [a fact finder]'s ultimate factual determination" that "rests upon an abstract formula." Soo Line, 97 Wis. 2d. at 60.
¶ 22. The more difficult question, however, is, having concluded that we should decide de novo which interest rate is the correct one to use in the valuation formula for this property, how are we to choose between them? I readily acknowledge my lack of expertise on the question and confess that I have no informed opinion on which interest rate will produce the "correct" valuation of federally subsidized housing projects. This panel has chosen to adopt the mortgage interest rate that was affirmed as having been properly applied in Bloomer Housing Ltd. Partnership v. City of Bloomer, 2002 WI App 252, 257 Wis. 2d 883, 653 N.W.2d 309. I agree with *799my colleagues that applying the Bloomer result is appropriate inasmuch as this court concluded that the determination in Bloomer was "consistent with the assessment manual." Id., ¶ 23. Moreover, because we are bound by our prior published decisions, see Cook v. Cook, 208 Wis. 2d 166, 189-90, 560 N.W.2d 246 (1997), I would find it hard to explain, in light of our discussion and the result reached in Bloomer, why the opposite result is the correct one here, as a matter of law.
¶ 23. I recognize that some persons may be firmly convinced, with ample justification, that the subsidized mortgage interest rate is indeed the correct rate to employ in order to arrive at the market value of subsidized housing. In at least one unpublished decision of this court (Rhinelander Family Housing v. City of Rhinelander, No. 96-2216, unpublished slip. op. (Wis. Ct. App. Jan. 14, 1997)), we upheld a board of review's assessment employing the subsidized rate. Our conclusion today, however, is that consistency on the point at issue is required, and that the rate to be employed in this "abstract formula" is not a fact that should be allowed to vary from Mineral Point to Bloomer to Rhinelander, based on the credibility of the witnesses who may appear before a board of review. If a different rule is to apply, it must come from the supreme court or the legislature, or perhaps from the DOR by way of clearer direction in the assessment manual.