過去文獻研究顯示，損益平穩化存有正反兩種競爭性意涵。從溝通私有資訊來看，若管理當局運用會計裁量權傳遞其對未來盈餘之評估，則損益平穩化可有效增進公司盈餘資訊內涵。從自利行為動機來看，若管理當局蓄意扭曲盈餘數字，則損益平穩化會使盈餘含有雜訊而損害公司盈餘資訊內涵。以上兩種觀念顯示，損益平穩化具有「增進」或「扭曲」資訊的效果，而究竟何種效果較具優勢，有待實證的探討。
本文以遞延所得稅資產備抵評價(簡稱DTA備抵評價)作為損益平穩化管理工具，探討其對公司未來盈餘、未來現金流量及盈餘持續性之影響，以及瞭解在兩稅合一制度與公司盈餘品質列入考慮情況下，損益平穩化所具有的「增進」或「扭曲」資訊效果是否會發生改變。損益平穩化是一種導源於人為操縱的盈餘管理事後效果，本文透過「回溯處理法」之運用，瞭解管理當局如何透過DTA備抵評價以達成損益平穩化目標。
本文實證結果發現：（1）DTA備抵評價變動之損益平穩化能使盈餘及未來現金流量更具資訊性，當期股價變動反映更多的未來盈餘及未來現金流量資訊，且損益平穩化愈大的公司，未來盈餘反應係數及未來現金流量反應係數也愈高；（2）DTA備抵評價變動之損益平穩化可提昇盈餘資訊性，增加當期盈餘與未來盈餘之盈餘持續性；（3）不管DTA備抵評價變動之損益平穩化會增進或扭曲未來盈餘資訊，公司在兩稅合一後之盈餘資訊性，均較兩稅合一前為大；（4）盈餘品質的好壞對未來盈餘資訊性的影響有顯著差異，惟無法確定是增進或扭曲未來盈餘資訊性，本文認為盈餘品質本身就包含某種程度的未來盈餘資訊性，與管理當局是否再從事損益平穩化並無一定關聯；（5）管理當局會有動機利用DTA備抵評價進行盈餘管理，當回溯項目的變異數愈大時，迴歸係數的估計值愈為負，且當平穩化誤差愈大，其迴歸係數的估計值愈接近零。

Prior research indicates that income smoothing has positive/negative competing implications. Under communicating private information perspectives, income smoothing effectively improves earnings informativeness if managers use their accounting discretion to communicate their assessment of future earnings. Under self-interest motivation perspectives, income smoothing makes earnings noisier and impares earnings informativeness if managers intentionally distort the earnings numbers. Two key concepts suggest that income smoothing has improving-versus-garbling debate. Which effect dominates in a cross-sectional setting is an open/empirical question.
The main purpose of this paper is to analyze the impact of income smoothing on future earnings, future cash flow and earnings persistence when managers choose the valuation allowance of deferred taxes assets (DTA hereafter) as an income-smoothing tool. Moreover, the article also attempts to understand whether such improving/garbling effect will be changed as integrated taxes system or earnings quality actually exists. An income smoothing is an ex-post effect of earnings-management resulting from managers’ manipulation. I employ the backing-out approach to realize managers how to use valuation allowance of DTA to achieve income-smoothing goal.
Empirical results indicate that（1）Income smoothing of DTA valuation allowance change makes earnings and future cash flows more informative. Returns indeed can reflect more information about future earnings and future cash flows, and the FERC and FCFRC are higher for firms with greater smoothing.（2）Income smoothing of DTA valuation allowance change can enhance earnings informativeness, and it also can improve the earnings persistence between current earnings and future earnings.（3）Regardless of the improveness or garbleness for earnings informativeness that income smoothing of DTA valuation allowance can do, the earnings informativeness after the integrated taxes system is higher than that before the integrated taxes system.（4）Earnings informativeness has significant difference between good earnings quality and bad earnings quality, but both of them can’t be identified which is improved/garbled. The main reason is that earnings quality itself contains some earnings informativeness, and it has no relation with the income smoothing.（5）Managers have incentives to exploit valuation allowance of DTA to manage earnings. When the variance of the item backed out is higher, the regression coefficient is more negative, and when the error of income smoothing variance continuously increases, the estimate of regression coefficient will be close to zero.

一、中文文獻
汪瑞芝、陳明進，2002，兩稅合一前後上市公司資本結構之實證研究，2002會計理論與實務研討會論文集，台北大學會計系編印。
---------、---------，2004，兩稅合一制前後上市公司股利發放之實證研究，管理評論，第二十一卷第二期，頁257-278。
吳清在、林松宏，2003，遞延所得稅資產備抵評價之決定因素及價值攸關性：台灣上市公司之實證研究，中華會計學刊，第三卷，第二期，頁201-236。
----------, ----------, 陳亭如，2004，兩稅合一是否改變「營利事業所得稅」之股價攸關 性，實踐大學高雄校區2004管理與創意研討會。
吳玉萍，2002，兩稅合一與企業盈餘管理行為之關聯性研究，國立成功大學會計學研究所碩士論文。
李芳倖，1998，會計方法選擇與負債比率及高階主管報酬之關連性研究，國立成功大學會計學研究所碩士論文。
呂政哲，2006，遞延所得稅資產備抵評價損益平穩化及訊息傳遞之研究，國立成功大學會計學研究所碩士論文。
林松宏、吳清在，2005，遞延所得稅資產備抵評價組成因子之研究，中華會計學刊，第六卷，第一期，頁29-58。
林娟慧，2005，遞延所得稅資產備抵評價之資訊內涵及股價資訊性：台灣上市公司之實證研究，國立成功大學會計學研究所碩士論文。
財團法人中華民國會計研究發展基金會，1994，「財務會計準則公報第二十二號：所得稅之會計處理準則」。
財團法人中華民國會計研究發展基金會，1999，「財務會計準則公報第二十二號：所得稅之會計處理準則」，最新修訂版。
徐景亮，1992，美國新所得稅會計處理準則（上），會計研究月刊，第八十七期，頁107-115。
----------，1992，美國新所得稅會計處理準則（中），會計研究月刊，第八十八期，頁51-88。
----------，1992，美國新所得稅會計處理準則（下），會計研究月刊，第八十九期，頁146-152。
孫克難，1997，兩稅合一方案之檢討與改進，兩稅合一研討會實錄，孫運璿學術基金會贊助，中華經濟研究院，頁55-106.
孫明德，1998，兩稅合一對企業財務決策影響之探討，中興大學企業管理研究所碩士論文。
陳依依，1998，遞延所得稅資產評價之實證研究，國立中正大學會計學研究所未出版碩士論文。
張至誼，2001，遞延所得稅資產評價之盈餘管理探討，國立台灣大學會計學研究所碩士論文。
張慧珊，2002，兩稅合一制度對於股權評價之影響研究，國立台灣大學會計學研究所博士論文。
張仲岳，梁鈺娟，所得稅暨退休金會計準則公報攸關性資訊品質之探討，會計評論，第33期，頁27-55，2001。
黃瑞靜、徐守德、廖四郎，2001，兩稅合一對公司價值、股利政策與資本結構之影響----動態資本結構模型之應用與台灣產業的實證研究，管理評論，第二十卷第二期，頁55-86。
管夢欣，1993，長期性資產出售交易與盈餘操縱行為之關聯性實證研究，國立台灣大學會計學研究所碩士論文。
二、英文文獻
Albornoz, B. G., and J. J. Alcarria. 2003. Analysis and diagnosis of income smoothing in Spain. European Accounting Review 12 (3)：443-463.
Albrecht, W. D., and F. M. Richardson. 1990, Income smoothing by economy sector, Journal of Business Finance and Accounting (Winter)：713-730.
Allayannis, G., and J. P. Weston. 2003. Earnings volatility, cash flow volatility, and firm value. Working paper. University of Virginia.
Amoako-Adu, B. 1983. Corporate valuation and personal taxes：Extension and application to Canada, The Financial Review 18 (November)：281-291.
----------, M. Rashid, and M. Stebbins, 1992. Capital gains tax and equity values：Empirical test of stock price reaction to the introduction and reduction of capital gains tax exemption, Journal of Banking and Finance 16：275-287.
Arya, A., J. Glover, and S. Sunder. 1998. Earnings management and the revelation principle. Review of Accounting Studies 3：7-34.
Amir, E., M. Kirschenheiter, and K. Willard. 1997. The valuation of deferred taxes, Contemporary Accounting Research Vol. 14No.4 (Winter): 597-622.
Ball, R, and P. Brown, 1968. An empirical evaluation of accounting income numbers. Journal of Accounting Research (Autumn)：159-178.
Bao, B-H, and D-H Bao. 2004. Income smoothing, earnings quality and Firm valuation, Journal of Business Finance and Accounting 31(9)＆(10)：1525-1557.
Barth, M. E., J. A. Elliott, and M. W. Finn. 1999. Market rewards associated with patterns of increasing earnings. Journal of Accounting Research 37 (Autumn)：387-413.
Bartov, E. 1993. The timing of asset sales and earnings manipulations. The Accounting Review. Vol. 50 (January)：840-855.
----------, and P. Mohanram. 2004. Private information, earnings manipulations, and executive stock option exercises. The Accounting Review 79 (4)：889-920.
Barner, A., J. Ronen and S. Sadan. 1976. Classificatory smoothing of income smoothing with extraordinary item. The accounting review (January): 111.
Bauman, C. C., and M. P. Bauman. 2000. The deferred tax asset valuation allowance as a strategic accounting choice. Working paper, University of Wisconsin-Milwaukee , University of Illinois at Chicago.
Beaver, W., R. Lambert, and D. Morse, 1980. The information content of security prices. Journal of Accounting and Economics 2：3-28.
----------, ---------, and S. Ryan, 1987. The information content of security prices: A second look. Journal of Accounting and Economics 9：139-158.
----------, 2002. Perspectives on recent capital market research. The Accounting Review (April)：453-474.
Beidleman, C. 1973. Income smoothing: The role of management. The Accounting Review 48 (4)：653-667.
Burgstahler, D., W. B. Elliott, and M. Hanlon. 2002. How firms avoid losses：Evidence of use of the net deferred tax asset account. Working paper. University of Washington.
Bushee, B. J., 1998. The influence of institutional investors on myopic R&D investment behavior. Accounting Review 73 (July)：305-333.
Chaney, P. K., and C. M. Lewis. 1998. Income smoothing and underperformance in initial public offerings. Journal of Corporate Finance 4：1-29.
Chao, C. L., R. L. Kelsey, S. M. Horng, and C. Y. Chiu. 2004. Evidence of earnings management from the measurement of the deferred tax allocation account. The Engineering Economist 49 (1)：63-93.
Collins, D. W., S. P. Kothari, J. Shanken and R. Sloan, 1994. Lack of timeliness and noise as explanations for the low contemporaneous return-earnings association. Journal of Accounting and Economics 18：289-324.
DeAngelo, L. 1986. Acountimg numbers as market valuation substitutes: A study of managent bouyouts of public shareholders. Accounting Review 61:400-420.
Dechow, P. M., R. G. Sloan, and A. P. Sweeney. 1995. Detecting earnings management. The Accounting Review 70 (April): 193-225.
Defond, M., and C. W. Park. 1997. Smoothing income in anticipation of future earnings,. Journal of Accounting and Economics 23 (July)：115-139.
Demski, J. S. 1998. Performance measure manipulation. Contemporary Accounting Research 15 (3)：261-285.
---------, and H. Frimor. 1999. Performance measure garbling under renegotiation in multi-period agencies. Journal of Accounting Research 37(Supplement)：187-214.
Dhaliwal, D., M. Frankel and R. Trezevant. 1994. The taxable and book income motivations for LIFO layer liquidations. Journal of Accounting Research (Autumn)：278-289.
Durnev, A., R. Morck, B. Yeung, and P. Zarowin. 2003. Does greater firm-specific return variation mean more or less informed stock pricing？Journal of Accounting Research Vol. 41 (December)：797-836.
Durnev, A., R. Morck, and B. Yeung. 2004. Value-enhancing capital budgeting and firm-specific stock return variation. Journal of Finance Vol. 59 No. 1：65-105.
Financial Accounting Standards Board (FASB), 1987, “Accounting for Income Taxes,” Statement of Financial Accounting Standards No.96, Norwalk. CT: FASB.
----------, 1992, “Accounting for Income Taxes,” Statement of Financial Accounting Standards No. 109, Norwalk. CT: FASB.
Francis, J., R. LaFond, and K. Schipper. 2004. Costs of equity and earnings attributes. The Accounting Review 79 (4)：967-1010.
Frank, M. M., and S. O. Rego. 2006. Do managers use the valuation allowance account to manage earnings around certain earnings targets？ Working paper, University of Iowa.
Fudenberg, D., and J. Tirole. 1995. A theory of income and dividend smoothing based on incumbency rents. Journal of Political Economy 103 (1)：75-93.
Gelb, D. S., and P. Zarowin. 2002. Corporate disclosure policy and the informativeness of stock prices. Review of Accounting Studies (March)：33-52.
Ghosh, A., Z. Gu, and P. C. Jain. 2005. Sustained earnings and revenue growth, earnings quality, and earnings response coefficients. Review of Accounting Studies 10：33-57.
Gordon, M. J. 1964. Postulates, principles and research in accounting. The Accounting Review 39 (2)：251-263.
Gordon, E. A., and P. R. Joos. 2004. Unrecognized deferred taxes : Evidence from the UK. The Accounting Review (Jan). 97-124.
Graham, J. R., C. R. Harvey, and S. Rajgopal. 2005, The economic implications of corporate financial reporting. Journal of Accounting and Economics 40: 3-73.
Guay, W. P., S. P. Kothari, and R. L. Watts. 1996. A market-based evaluation of discretionary accruals models, Journal of Accounting Research 34 (Supplement)：83-105.
Gujarathi, M. R. and R. E. Hoskin. 1992. Evidence of earnings management by the early adoption of SFAS No. 96. Accounting Horizons：18-31.
Gaver J.J.1; Gaver K.M.; Austin J.R. 1995. Additional evidence on bonus plans and income management. Journal of Accounting and Economics 19: 3-28.
Hagerman, R., and M. Zmijewski. 1981. An income strategy approach to the positive theory of accounting standard setting/choice. Journal of Accounting and Economics (August)：129-149.
Hand, J. R. 1989. Did firms undertake debt-equity swaps for an accounting paper profit or true financial gain？The Accounting Review. (October)：587-623.
Healy, P. 1985. The effect of bonus schemes on accounting decision. Journal of Accounting and Economics (April)：85-107.
----------, and J. Wahlen. 1999. A review of the earnings management literature and its implications for standard setting. Accounting Horizons：365-383.
Heiman-Hoffman, V. B., and J. M. Patton. 1994. An experimental investigation of deferred tax asset judgments under SFAS No. 109. Accounting Horizons (March): 1-7.
Hepworth, S. R. 1953. Smoothing periodic income, The Accounting Review (January)：32-39.
Holland, K., and Richard H. G. Jackson. 2003. Earnings management and deferred tax. Accounting and Business Research. Forthcoming.
Hunt, A., S. Moyer, and T. Shevlin.2000, Earnings volatility, earnings management, and equity value. Working paper, University of Washington.
Hussainey, K., T. Schleicher, and M. Walker. 2003. Undertaking large-scale disclosure studies when AIMR-FAF rating are not available: the case of prices leading earnings. Accounting and Business Research 33 (4)：275-294.
Jiambalvo, J., S. Rajgopal, and M. Venkatachalam. 2002. Institutional ownership and the extent to which stock prices reflect future earnings. Contemporary Accounting Research 19 (Spring)：117-145.
Jones, J. 1991. Earnings management during import relief investigations. Journal of Accounting Research 29 (2)：193-228.
Kamin, J. Y., and J. Sadan. 1978. The smoothing of income numbers: some empirical evidence on systematic differences among management-controlled and owner-controlled firms, Accounting Organizations and Society, 3 (2):141-157.
Kinny, M., and W. Wempe. 2001. The effect of inventory valuation method and earnings management incentives on JIT adoption. Working paper. University of Washington, St. Louis.
Kirschenheiter, M., and N. Melumad. 2002. Can Big Bath and earnings smoothing co-exist as equilibrium financial reporting strategies? Journal of Accounting Research 40 (3)：761-796.
Kothari, S. P., and R. Sloan. 1992. Information in prices about future earnings: Implication for earnings response coefficients. Journal of Accounting and Economics 15：143-171.
Kumar, K. R. and G. Visvanathan, 2003. “The information content of the deferred tax valuation allowance,” The Accounting Review 78 (April)：471-490.
Kang SH. and Sivaramakrishnan K. 1995. Issues in Testing Earnings Management and an Instrumental Variable Approach. Journal of Accounting Research 33：353-367.
Lambert, R. 1984. Income smoothing as rational equilibrium behavior. The Accounting Review 41 (4)：604-618.
Leuz, C., D. Nanda, and P. Wysocki. 2003. Investor protection and earnings management. Journal of Financial Economics 69 (3)：505-527.
Lim, S. C., and S. Lustgarten. 2002. Testing for income smoothing using the backing out method：Areview of specification issues. Review of quantitative Finance and Accounting 19 (3)：273-289.
Loomis, C. J. 1999, “Lies, demand lies, and managed earnings：The crackdown is here.”, Fortune (August 2)：75-92.
Lu, J. 2000. The valuation allowance for deferred tax assets and earnings management. Working paper, University of Southern California.
Lundholm, R., and L. A. Myers, 2002. Bringing the future forward：The effect of disclosure on the return-earnings relation. Journal of Accounting Research 40：809-939.
Marquardt, C., and C. Wiedman. 2005. Earnings management through transaction structuring：Contingent convertible debt and diluted earnings per share. Journal of Accounting Research 43 (2)：205-243.
Matsunaga, S. 1995. The effects of financial reporting costs on the use of employee stock options. The Accounting Review (January)：1-26.
Michelson, S., J. Jordan-Wagner, and C. Wootton. 2000. The relationship between the smoothing of reported income and risk-adjusted returns. Journal of Economics and Finance 24：141-159.
Miller, G., and D. Skinner, 1998, “Determinants of the valuation allowance for deferred tax assets under SFAS No.109,” Accounting Review. Vol.73. No.2 (April): 213-233.
Moehrle, S. 1997. Earnings management and restructuring charge reversals (income smoothing). Ph.D. Dissertation, Indiana University.+
Morse, O. D. 1987, Income smoothing and incentives：Empirical tests using accounting changes, The Accounting Review 62 (April)：358-377.
Myers, L. A., J. A. Myers and D. J. Skinner. 2005. Earnings momentum and earnings management. Working paper, University of Michigan.
Ohlson, J. 1995. Earnings, book values and dividends in equity valuation. Contemporary Accounting Research (Spring): 661-687.
Perry, S., and R. Grinaker. 1994. Earnings expections and discretionary research and development spending. Accounting Horizons (December)：43-51.
Phillips, J. D., M. Pincus, and S. O. Rego. 2003. Earnings management：New evidence based on deferred tax expense. The Accounting Review 78 (April)：491-521.
Ronen, J., and S. Sadan. 1981. Smoothing Income Numbers: Objectives, Means, and Implications. Boston, MA: Addison-Wesley Publishing Company.
Sankar, M., and K. R. Subramanyam. 2001. Reporting discretion and private information communication through earnings. Journal of Accounting Research 39 (2)：365-386.
Schipper, K. 1989, “Commentary：Earnings management,” Accounting Horizons (December): 91-102.
Schrand, C. and M. H .F. Wong. 2003. Earnings management using the valuation allowance for deferred tax assets under SFAS 109. Contemporary Accounting Research (Fall)：579-611.
Sloan, R. G. 1996. Do stock prices fully reflect information in accruals and cash flows about future earnings？The Accounting Review (July)：289-315.
Spence, M. 1973. Job market signaling. The Quarterly Journal of Economics 87 (3)：355-374.
Subramanyam, K. R. 1996. The pricing of discretionary accruals. Journal of Accounting and Economics 22：249-281.
Teoh, S., I. Welch, and T. Wong. 1998. Earnings management and the underperformance of seasoned equity offerings. Journal of Financial Economics 50 (1): 63-99.
Thomas, J., and H. Zhang. 2003. Value-relevant properties of smoothed earnings. Working paper, Yale University.
Trueman, B. and S. Titman. 1988. An explanation for accounting income smoothing. Journal of Accounting Research (Supplement)：127-139.
Tucker, J. W., and P. A. Zarowin, 2006, Does income smoothing imporove earnings informativeness？Accounting Review Vol. 81, No. 1：251-270.
Visvanathan, G. 1998. Deferred tax valuation allowances and earnings management, Journal of Financial Statement Analysis 3 (4): 6-15.
Wang, Z., and T. H. Williams. 1994. Accounting income smoothing and stockholder wealth. Journal of Applied Business Research 10 (Summer): 96-104.
Watts, R. L., and J. L. Zimmerman. 1978. Towards a positive theory of the determination of accounting standards. The Accounting Review 53 (January): 112-134.