自從美國安隆 (Enron)、世界通訊 (WorldCom)及全錄 (Xerox)公司等重大財務弊案爆發後,財務所得與課稅所得的關係一直是學者所重視的議題。但過去的研究大都著眼於財稅所得差異做探討,極少分別就財務所得和課稅所得來探討其資訊內涵。 本研究採用Hanlon, Laplante and Shevlin (2005)的三個檢定:投資組合報酬檢定、相對資訊內涵檢定及增額資訊內涵檢定,來檢視財務所得與課稅所得的資訊內涵。本文以1998年至2007年台灣上市公司作為研究樣本,最終樣本數為3,112筆公司/年度觀察值。 研究結果顯示:(1)在投資組合報酬檢定中,財務所得相較於課稅所得更能提供有用的資訊給投資人做決策,即財務所得的資訊價值相對大於課稅所得;(2)在相對資訊內涵檢定中,並無法驗證財務所得或課稅所得何者較能解釋股票報酬,顯示兩種所得資訊皆會被投資人用於投資決策上,即投資人並無特別偏好任一所得資訊;(3)在增額資訊內涵檢定中,顯示財務所得與課稅所得皆具有增額資訊內涵,即擁有兩種所得的資訊價值大於只擁有其中一種。由上述三個檢定結果可知,財務所得與課稅所得皆具有資訊內涵,即皆有存在價值。
Since the financial scandal of Enron, Worldcom and Xerox had been revealed, the relationship between financial income and taxable income has always been an important subject of debate for scholars. However, previous research studies were mostly focused on the discussion of book-tax differences, informative content regarding to financial income and taxable income are seldom discussed. Present research adopted three types of Hanlon, Laplante and Shevlin's (2005) tests: portfolio return tests, relative information content tests and incremental information content tests in examining the information content of financial income and taxable income. The subject used in this research is the listed companies in Taiwan between the year of 1998 to 2007. The number of sample used at the end is 3112 companies/annual observation. The research result shows: (1) according to portfolio return tests, as compare to taxable income, financial income is a better resource in providing useful information for investors in their decision making. In other words, financial income has a higher value in information than taxable income. (2) In relative information content tests, there is no indication of whether financial income or taxable income is better in explaining stock returns. It shows these two types of information are both used by investors in decision making. That is, investors do not have particular preference. (3) In incremental information content tests, it shows both financial income and taxable income have additional informative content. In other words, the value of these two types of information has higher value than having only one type of information. From the result of these three tests discussed above, financial income and taxable income both have informative content, which means both have existing value.