1. INTRODUCTION
In seeking for the optimal capital structure for profitable entrepreneurs, the existing controversies argue the propositions, contributed by Modigliani and Miller (1958) whose theories express the irrelevance of firms’ capital structure and the further-developed limited relaxations of the assumptions including income taxes. In addition, MM theories of personal income taxes, that offset the benefits from but not totally eliminate the overall advantages of corporate income tax, favors the debt finance for maximizing the wealth of shareholders, which are further assured by the study of Masulis (1982) that the use of debt could add more value to the firm in terms of tax shields.