(dissenting).
I respectfully dissent. The decision reached by the majority is not only contrary to well established law but potentially inequitable in its application.
No doubt the tax law revision about which Mark complains could constitute a substantial change of circumstances warranting modification in a given case. See, e.g., In re Marriage of Habben, 260 N.W.2d 401, 403 (Iowa 1977) (right to claim income tax deductions bears on financial ability to pay support and is thus proper subject of modification). Whether any change is “substantial,” however, turns on the “overall financial condition” of the parties at the time a modification is proposed. Page v. Page, 219 N.W.2d 556, 558 (Iowa 1974); see also Iowa Code § 598.21(8) (codifying not less than eighteen factors to be considered by the court before modifying a decree).
The problem with the present case is that we simply do not have before us a record that reflects the overall financial condition of these parties. Mark, whose burden it was to furnish such proof, palpably failed to do so. When asked, for example, to defend his self-serving testimony that he furnishes more than fifty percent of the children’s support he candidly replied: “I don’t have proof, but I just feel that if it were, you know, to be proved, that it could be proved.”
This court recently held that a decree should not be modified “unless its enforcement will be attended by positive wrong or injustice as a result of changed conditions.” In re Marriage of Bergfeld, 465 N.W.2d 865, 869 (Iowa 1991) (quoting Ellis v. Ellis, 262 N.W.2d 265, 267 (Iowa 1978)). The only changed condition cited by Mark is the amended tax code. I would concede that his faithful payment of child support, without the benefit of the tax deduction, may be inequitable. For the reasons that follow, however, I submit that it may be just as inequitable to deny this tax advantage to the custodial parent.
Under the court’s 1983 decree, a portion of Mark’s child support obligation of $9200 per year is considered payment toward real *266estate equity for which he will be reimbursed when the homestead is sold. Although not entirely clear on this record, that reimbursable sum appears to be $200 per month, or $2400 per year. This credit reduces his true child support obligation to $6800 per year. Given the current tax deduction of $2050 per dependent, see I.R.C. § 151(d)(1)(C) (1991), the majority opinion enables Mark to offset a substantial portion of his annual child support obligation. Cynthia, on the other hand, is deprived of that benefit, notwithstanding the fact that she bears the day-to-day responsibility for these children and, arguably, forty-nine percent of their financial support. The court of appeals has recognized the obvious inequity in such a situation. See In re Marriage of Eglseder, 448 N.W.2d 703, 705 (Iowa App.1989). So should we.
Without an adequate record, it is impossible to strike the proper balance in these equitable proceedings. The district court wisely rested its refusal to modify on this ground. We should affirm.
McGIVERIN, C.J., and LARSON, J., join this dissent.