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n there are information asymmetries between the ?rm?s management and its investors. He argued that management has better knowledge of the ?rm than the investors, and that management will try to avoid debt when the ?rm is performing poorly for fear that any debt default due to poor cash ?ow will result in their job loss. The information asymmetry may also explain why existing investors may not favor new equity ?nancing, as new investors may require higher returns to pensate for the risks of their investment thus diluting the returns to existing investors. Myers and Majluf (1984) later developed their socalled pecking order theory of ?nancing: . that capital structure will be driven by ?rms? desire to ?nance new investments preferably through the use of internal funds, then with lowrisk debt, and with new equity only as a last resort. In their theory, there is no optimal capital structure that maximizes the ?rm value. The ?nancial managers issue debt or equity purely according to the costs of capital. Subsequent empirical studies provide mixed evidence. Helwege and Liang (1996) found no empirical evidence for such a pecking order. Booth et al. (2020) found evidence supporting the theory in their 10country empirical study. Frank and Goyal (2020) tested the pecking order theory on a broad crosssection of publicly traded American ?rms for 1971 to 1998, and concluded that the theory was not supported by the evidence. Whilst large ?rms exhibited some aspects of pecking order behavior, the evidence was not robust to the inclusion of conventional leverage factors, nor to the analysis of evidence from the 1990s. . The tradeoff theory The tradeo? theory argues that there is an optimal capital structure that maximizes the ?rm value, but the tradeo? es in various forms. . TaxShield Bene?ts and the Financial Distress Cost of Debt One of the crucial assumptions of the MM (1958) model was that there is no taxation. Later work by Modigliani and Miller (1963), and Miller (1977) add tax e?ects into the original framework. An implication of this newer work was that ?rms should ?nance their projects pletely through debt in order to maximize corporate value. Clearly this contradicts reality in that debt constitutes only a fraction of ?rms? total capital. Subsequent theoretical work seeks an optimal capital structure which results from a tradeo? between the bene?ts of tax shield of debt and the costs of ?nancial distress of debt. According to this line of theory, the bene?ts of debt arise from its tax exemption, which implies that a higher debt ratio will increase the ?rm?s value. But the bene?ts can be o?set by costs of ?nancial distress, which may destroy the value of the ?rm. Thus the optimal capital structure is determined by the tradeo? between the taxfree bene?ts of debt and the distress costs of debt see Figure 1. De Angelo and Masulis (1980), Ross (1985) and Leland (1994) have shown that, in the presence of taxation, it is advantageous for a ?rm with safe, tangible assets and plenty of taxable ine to take a high debtequity ratio to avoid high tax payments. For a ?rm with poorer performance and more intangible assets, it is better to rely on equity ?nancing. One problem with the theories based on consideration of the taxshield bene?ts is that they cannot explain why capital structures vary