A Simple Neutrality Result for Movements between Income and Consumption Taxes

In this note the possibility is demonstrated that a movement between a broadly based income tax and a consumption tax in a two-period consumption loan model can be completely accommodated by interest rate changes which leave real intertemporal consumption plans unchanged. Income and consumption taxes are both broadly based taxes, the former taxing all potential consumption in any period and the latter actual consumption. Lenders and borrowers face the same prices under both tax regimes and movements between the two can, in this simple model, be wholly accommodated by interest rate changes leaving intertemporal consumption plans unaffected. This result contrasts with the conventional argument in favor of a consumption tax in preference to an income tax on the basis of lack of distortion of savings behavior. It is not suggested that because of this result exact monetary accommodation to consumption income tax variations will occur in all circumstances, but it seems to be of interest to note that such adjustments are possible and these appear not to have been previously considered. The traditional argument for the distorting effects of an income tax over a consumption tax is often made in a simple two-period intertemporal consumption choice model. If an individual receives income Y,, YK in each of two periods and if the interest rate is r, then, so the argument goes, the slope of an individual's budget constraint between current and future consumption (C, and C2) is not disturbed by a consumption tax, whereas it is under an income tax. If interest is both taxable as a receipt and deductible as an expense under the income tax, and the marginal tax rate t is assumed to apply under both the income and consumption tax,' the slopes of the consumer budget constraint under the three alternative regimes are