【正文】 st the marginal direct costs of ?nancial distress or direct bankruptcy costs. Additional factors can be included in this tradeoff framework. Other costs than direct costs of ?nancial distress are agency costs of debt . Often cited examples of agency costs of debt are the underinvestment problem, the asset substitution problem ， the “play for time” game by managers, the “unexpected increase of leverage (bined with an equivalent pay out to stockholders to make to increase the impact),” the “refusal to contribute equity capital” and the “cash in and run” game . These problems are caused by the difference of interest between equity and debt holders and could be seen as part of the indirect costs of ?nancial distress. Another bene?t of debt besides the PVTS is the reduction of agency costs between managers and external holders of equity. Jensen and Meckling argue that debt, by allowing larger managerial residual claims because the need for external equity is reduced by the use of debt, increases managerial effort to work. In addition, Jensen [23] argues that high leverage reduces free cash (?ow) with less resources to waste on unpro?table investments as a result. The agency costs between management and external equity are often left out the tradeoff theory since it assumes managers not acting on behalf of the shareholders (only) which is an assumption of the traditional tradeoff theory. In Myers’ and Myers and Majluf’s pecking order model there is no optimal capital structure. Instead, because of asymmetric information and signaling problems associated with external ?nancing, ?rm’s ?nancing policies follow a hierarchy, with a preference for internal over external ?nance, and for debt over equity. A strict interpretation of this model suggests that ?rms do not aim at a target debt ratio. Instead, the debt ratio is just the cumulative result of hierarchical ?nancing over time. . Original examples of signaling models are the models of Ross and Leland and Pyle. Ross suggests that higher ?nancial leverage can be used by managers to signal an optimistic future for the ?rm and that these signals cannot be mimicked by unsuccessful ?rms. Leland and Pyle [30] focus on owners instead of managers. They assume that entrepreneurs have better information on the expected cash ?ows than outsiders have. The inside information held by an entrepreneur can be transferred to suppliers of capital because it is in the owner’s interest to invest a greater fraction of his wealth in successful projects. Thus the owner’s willingness to invest in his own projects can serve as a signal of project quality. The value of the ?rm increases with the percentage of equity held by the entrepreneur relative to the percentage he would have held in case of a lower quality project. The stakeholder theory formulated by Grinblatt and Titman [19] suggests that the way in which a ?rm and its non?nancial stakeholders interact is an important determinant of the ?rm’s optimal capital structure. Non?nancial stakeholders are those parties other than the debt and equity holders. Non?nancial stakeholders include ?rm’s customers, employees, suppliers and the overall munity in which the ?rm operates. These stakeholders can be hurt by a ?rm’s ?nancial difficulties. For example customers may receive inferior products that are difficult to service, suppliers may lose business, employees may lose jobs and the economy can be disrupted. Because of the costs they potentially bear in the event of a ?rm’s ?nancial distress, non?nancial stakeholders will be less interested ceteris paribus in doing business with a ?rm having a high(er) potential for ?nancial difficulties. This understandable reluctance to do business with a distressed ?rm creates a cost that can deter a ?rm from undertaking excessive d