¶1This is certiorari to review the decision of Judges Frazer and Carpenter in refusing a mandamus to compel a modification of the assessment of the estate in relators’ hands for the purpose of taxation. The facts, as disclosed by the return, are that the relators have credits in their hands amounting to $261,000, and that the estate is responsible, under the covenants of a lease of property known as the “Biddle House,” in Detroit, for rent for 75 years at an estimated rental of $16,000. The rent fluctuates on revaluations at intervals. The claim is that the assessors should have allowed the present value of the amount to grow due as rent, as an offset against these credits, and mandamus was asked to *457require the common council to so modify the assessment as to give relators the benefit of the reduction.
¶2The statute (section 9, Act No. 206, Pub. Acts 1898) exempts from taxation “so much of the debts due or to become due as shall equal the amount of bona fide and unconditional debts by the person owing.” The contention by the counsel for the relators is that this statute is to be construed as meaning that so much of the debts due the taxpayer as shall equal the bona fide and unconditional debts owing by the taxpayer is exempt; and itfis contended that the engagement to pay rent on this lease is a bona fide and unconditional debt owing by the estate, within the meaning of the statute. We think it is not such an unconditional debt as is contemplated by this statute. It is rather a charge upon an estate, which is supposed to equal the value of the estate to be enjoyed. It is no more an unconditional debt than would be a contract to pay for wheat, or any other commodity, to be delivered at a future time, at a stated price. In either case there is an obligation to pay, conditional upon the enjoyment of the estate or the receipt of the commodity; and, though the engagement may be absolute, we think it is not a debt, within the meaning of the statute, the aim of which is to offset against credits the unqualified obligations owing by the person taxed, which decrease his taxable property in fact.
¶3The order of the circuit court is affirmed.