收益不确定条件下债务税蔽模型——对MM税蔽模型的扩展

Debt Tax Shield Model under Revenue Uncertainty ——Extension to MM's Tax Shield Model

本文首先回顾了一些学者对债务融资税蔽的认识,这些认识存在一些误区。我们认为债务税蔽不仅与所得税率有关,而且与企业的收益波动有关。在收益不确定的情况下,如果企业的税前利润为正,则债务融资税蔽是充分的;如果税前利润为负但息税前利润大于零,则债务融资可以获得部分税蔽;如果息税前利润小于零,则不能获得任何税收收益。

This study has reviewed the understanding of the tax benefit of debt financing of some scholars, there are some mistaken ideas in the understanding. We think that debt taxes shields not only relate to tax rate of income, but also relate to the fact that the incomes of enterprises fluctuate. In a situation that the revenue is uncertain, if the pretax profits are positive, enterprises can get abundant tax shield of debt financing; If the pretax profits are negative and EBIT is more than zero, enterprises can get some of tax shield of debt financing; If EBIT is less than zero,enterprises can＇t obtain any tax benefit from debt financing.