Depreciation and interest deductions and the effect of the corporation income tax on investment

In this paper, we examine the effect of the corporation income tax on the investment decision of the firm particularly with respect to the role of interest and depreciation deductions in determining the neutrality of the tax. We demonstrate the need for introducing a constraint on corporate borrowing before a meaningful analysis of the firm's behaviour under certainty is possible. The effect of a given tax and deduction scheme on the firm's investment decision is found to depend on the form of this constraint. We then relate our results to that of earlier authors and indicate some problems with their analyses.