This study examines whether earnings guidance contributes to investor short-termism -- excessive focus on a firm's short term performance and insufficient consideration of its long-term value creation potential. Using an adaptation of Ohlson's (1995) valuation model, I find that investors place significantly higher (lower) weight on short-term (long-term) earnings of quarterly guidance firms than on the corresponding earnings of non-guidance firms. Further tests indicate that the differential weighting cannot be fully explained by measurement errors, earnings properties, risk, or accuracy of analysts' forecasts. For a sample of guidance initiating firms, I find no differential valuations of firm value components before the initiation of guidance, but large differential valuations after guidance initiation. In contrast, for guidance discontinuation firms, I find that investors shift their focus from short-term to long-term earnings after the discontinuation of guidance. Together, the results support critics' claim that quarterly guidance contributes to short-term fixation in the market. / text

本研究之目的在探討，上期對本期所做之盈餘預測與本期實際盈餘間誤差所產生之未預期盈餘，對於管理階層在本期預測下期盈餘以及財務分析師針對該預測所作之預測修正，即對於該兩者的攸關性是否會隨著34號公報之實施而提高，也就是說，在34號公報實施之後，未預期盈餘對於管理當局盈餘預測以及分析師預測修正之影響，是否會更加顯著相關。 實證結果顯示，不論34號公報適用前後，管理當局盈餘預測與未預期盈餘之間皆具有攸關性，但在34號公報適用之後，兩者之間的顯著性並未增強；而另一方面，在34號公報適用前後，財務分析師盈餘預測修正與未預期盈餘之間皆具有攸關性，且在34號公報適用之後，兩者之間的顯著性有增強。 / This thesis examines whether the issuance of SFAS No.34 can heighten the association between the unexpected earnings for current period and the management earnings forecast for the next period. This research also examines if the issuance of SFAS No.34 will heighten the relationship between the unexpected earnings for current period and the analysts’ revision of the management earnings forecast for the next period. The unexpected earnings mean the difference between the earnings forecast for current period and the actual earnings in current period This thesis finds that there is a negative association between management earnings forecast and the error of the expected earnings whether SFAS No.34 has been issued or not, but the issuance of SFAS No.34 doesn’t heighten the association between the management earnings forecast and the error of the expected earnings. Besides, the result of the research shows that there is a positive relationship between the analyst’s revision of the management earnings forecast and the error of the expected earnings. Furthermore, the relationship is heightened by the issuance of SFAS No.34.

本研究主要探討產業專家會計師事務所對其受查企業管理當局自願性盈餘預測品質之影響，文中自願性盈餘預測之品質分別就盈餘預測之發布意願、揭露盈餘預測方式之精確性、盈餘預測之準確性、盈餘預測之穩健性四部分來探討。本研究係以2009年之S&P 500公司作為研究對象，樣本期間為2000年至2009年。實證結果顯示：產業專家會計師事務所之受查企業相較於非產業專家會計師事務所之受查企業，較有意願去發布管理當局自願性盈餘預測，也傾向於以較具體精確之方式去揭露盈餘預測，且其盈餘預測之準確性亦較高，但其與受查企業管理當局自願性盈餘預測之穩健性則無顯著關聯性。顯示產業專家會計師事務所與其受查企業管理當局自願性盈餘預測之間存在關聯性，產業專家會計師事務所能提升其受查企業管理當局自願性盈餘預測之品質。 / This paper examines the effects of auditor industry specialization on voluntary management earnings forecasts. This paper uses the incidence of issuing voluntary management earnings forecasts, forecast specificity, forecast accuracy, and forecast conservatism to measure the quality of voluntary management earnings forecast. Based on the sample of 2009 S&P 500 companies spanning from 2000 to 2009, the results indicate that firms audited by industry specialist are more likely to issue earnings forecasts, and their forecasts are more specific. In addition, these forecasts tend to be more accurate. Taken together, the empirical evidence is consistent with the prediction that the auditor industry specialization is associated with voluntary management earnings forecasts; that is, auditor industry specialization helps to enhance the quality of voluntary management forecasts.

本研究主要探討公司國際化程度及公司治理對管理當局自願性盈餘預測行為之影響，而本研究係以2009年公布之美國S&P 500公司作為研究對象，研究期間為2002年至2007 年。實證結果顯示：(1)企業國際化程度與管理當局揭露自願性盈餘預測之意願無顯著關聯性；(2)企業國際化程度越高，管理當局自願性盈餘預測之準確性越高；(3)企業國際化程度越高的情形下，公司治理之良窳與管理當局自願性盈餘預測間無顯著關聯性；(4)企業國際化程度越高，公司治理機制越良好，管理當局自願性盈餘預測準確性越高。 / This study investigates the effects of internalization and corporate governance on voluntary management earnings forecasts. Based on a sample of 2009 S&P 500 companies spanning from 2002 and 2007, I do not find the issuance of voluntary management earnings forecasts to be related with the degree of internalization and the quality of corporate governance. However, the empirical results indicate that the accuracy of management earnings forecasts is positively associated with the degree of internalization and the quality of corporate governance.

企業自願性盈餘預測屬資訊公開體系的一環，我國相關法令雖要求自願性盈餘預測必須於發布後二日公告，並經會計師核閱，且錯誤超過盈餘之20%必須要強制修正，但是實務上企業管理者常游走法律邊緣，而主管機關也沒有嚴格執法，使得公司盈餘預測常被詬病，甚至有淪為股票炒作工具之說，嚴重損害投資人的利益，這樣的現象或許可以透過規範董事會的組成進而強化公司監管的機制來獲得解決。先前有關盈餘預測的研究並沒有將公司監管機制以及董事會中的家族因素納入考量，因此，本研究試圖以公司監管的角度出發，並加入家族因素，以橫斷面迴歸分析的方法，探討一般董事會結構及公司監管機制（自變數）與自願性盈餘預測行為（應變數）之關聯性。 在自變數中，一般董事會結構方面除了包括董事會持股比例外，尚採用Cubbin and Leech（1983）的表決機率模型，做為家族企業判斷的依據，以便將家族因素納入考量，而公司監理機制方面則包括非關係企業法人董事、法人投資機構以及法人以外第二勢力等三項。在應變數中，本研究將應變數依照是否發布自願性盈餘預測、自願性盈餘預測發布次數以及自願性盈餘預測發布準確性等，分為三個主題依序探討。研究結論如下： 1.董事會持股愈高，企業愈不會發布自願性盈餘預測，一旦發布，錯誤的機會較高。 2.家族愈能掌控董事會時，企業愈有發布自願性盈餘預測的意願，一旦發布，修正的機會並不高。而家族企業中，家族持股愈高時，發布自願性盈餘預測的意願愈強烈，但是準確性也愈低。 3.董事會中法人第二勢力存在（非關係企業法人持股大於3%），同時持股較高時，會提高企業對外發布自願性盈餘預測的意願，其修正預測的機會比較低。 4.董事會中法人以外第二勢力存在，同時持有股數較高時，愈會降低自願性盈餘預測修正的機會，而盈餘預測準確性也會比較高。 5.公司董事會被家族所掌控時，在第一次盈餘預測發布時，較有可能發布比實際情況樂觀的盈餘預測，而公司當年度有好消息或是規模較大時，也較可能發布比實際情況樂觀的盈餘預測。至於負債比率較大的公司，發布盈餘預測的態度反而比較保守，較可能出現低估的情形。

本研究旨在探討管理當局發佈自願性盈餘預測意願、預測精確度、預測型態與管理當局能力之關聯性，並進一步檢測能力較佳之管理當局所發佈之盈餘預測對投資人是否具增額資訊內涵。 實證分析結果顯示管理當局能力與管理當局發佈盈餘預測之機率呈顯著正相關，亦即管理當局能力愈好，發佈盈餘預測之機率愈高；再者，本研究發現能力愈佳之管理當局，其盈餘預測之精確度亦會較高；而實證結果亦顯示當管理當局能力較好時，較願意以資訊量較多之完整式財務預測型態發佈財務預測。增額測試結果則顯示市場對於能力較佳之管理當局發佈之自願性盈餘預測反應程度較高。 / The primary objective of this thesis is to explore whether the managerial ability is related to management earnings forecast, earnings forecast accuracy , and disclosure format. Additionally, this thesis investigates whether managerial ability increases the informativeness of management earnings forecast for (potential) investors. Empirical results show that managers with superior ability tend to announce management earnings forecast and when managers have better ability, they shall announce more precise management earnings forecast. About disclosure format, this thesis finds that managers with superior ability prefer to announce complete earnings forecasts than simple ones. Additionally, market reaction will be more to the informativeness of management earnings forecast which made by managers with better ability.