Abstract: There is an ongoing debate on whether risk-taking incentives align risk-averse managers’ interests with those of shareholders or whether such incentives lead to excessively risky firm and leverage policies. In this study, we shed light on this debate by using CEO risk-taking incentives, measured by the sensitivity of CEO wealth to changes in stock return volatility (Vega), and explain how Vega affects firms’ security issuance and repurchase activities. In general, we find that a higher Vega increases (decreases) the likelihood of debt issuance (share issuance) and it decreases (increases) the propensity of debt retirement (share repurchase). However, in high-levered firms, the positive effect of Vega on debt issuance and the negative influence of Vega on debt retirement are diminished. One the other hand, for equity issuance and repurchases, high leverage does not seem to alter the impact of Vega. These findings have three main implications: 1) in general, CEO risk-taking incentives (Vega) do affect the financing decisions of firms by increasing firms’ degree of leverage, (2) when existing leverage is high, CEO risk-taking incentives do not seem to induce CEOs to take excessive financial risks through debt issuance, but such incentives encourage them to continue repurchasing shares that would lead to even higher debt ratios and non-operational risks, and (3) firms with high Vega do not seem to adopt target debt ratios. JEL Classification: G30, G32, J33

從1990年起，美國財政部發佈之消息顯示，公司之財稅差異不斷擴大，每年預估之財稅收入不斷向下修正，公司是否透過財務會計準則與稅法間不同規定所產生之差異進行避稅行為，引發政府機關與學者之關切。另一方面，盈餘管理為近年來熱門的探討主題之一，因此，財稅差異是否為其中一種手法，為本研究探討之主題。 過去學者透過稅前財務所得之變動及組成來判斷盈餘管理之存在，本研究則透過財稅差異之變動幅度與稅前財務所得之連動關係，及過去文獻用以衡量盈餘管理之變數來測試財稅差異是否與盈餘管理有關。另一方面，管理階層獎酬為產生盈餘管理行為的重要誘因之一，故分析管理階層之誘因是否會影響財稅差異之幅度，也納入本研究探討之主題。最後，本研究從公司治理機制中財務報表之角度，分析公司治理機制是否對於財稅差異幅度有同樣之影響，加強本研究之結果。 本研究之實證結果顯示：（1）財稅差異之幅度可能為盈餘管理操弄手法之一；（2）管理階層獎酬誘因越大，透過財稅差異操弄盈餘之幅度越大，尤其以管理階層所獲取之現金紅利具有最高關聯性，且有持續三年影響效果；（3）公司治理機制之良莠，影響財稅差異幅度；（4）當財務所得大於課稅所得或是大於零時，管理階層透過財稅差異操弄盈餘之情形更加顯著。 / According to the report published by Internal Revenue Service in 1990s, corporate tax-book differences trends increasingly and consequently brings about the government and researchers’ concerns about whether managers’ incentives influence the way they manipulate the earnings by different regulation among financial income and taxable income. In this study, I will first develop the model to measure the relation between earnings management and tax-book differences. On the other hand, compensation incentives are the major factors in earnings management. Therefore, the more the incentives, such as higher bonus, stockholding and bonus rates, the more possibilities earnings management. In addition, to enhance the result of the analysis; variables of corporate governance which have been testified as having connection with earnings management are added as robust test. The result demonstrates that corporate tax-book difference is related to earning management, and that compensation incentives are the motives of managers to manipulate financial income for extra return. Moreover, corporate governance is also another factor which affects the degree of earnings management. Besides, this situation becomes more obvious when financial income is larger than taxable income or when it appears to be zero. This study may help explaining why large tax- book gaps trend increasingly.