本文旨在探討遞延所得稅中虧損扣抵遞轉是否具有價值攸關性。實證分析結果發現：(1)從衡量觀點來看，「可減除暫時性差異所得稅影響數」與「虧損扣抵」具有財產權性質，與股價成正向關係；(2)從資訊觀點來看，有「租稅後抵」公司其異常盈餘較無「租稅後抵」公司不具價值攸關性，間接證實租稅後抵雖具有未來租稅節省效果，但也傳遞出公司未來會有較高損失的可能性；(3)從評價觀點來看，有「遞延所得稅資產備抵評價」的公司其異常盈餘較無「遞延所得稅資產備抵評價」公司不具價值攸關性，間接證實遞延所得稅資產備抵評價雖是管理當局進行盈餘管理的有利工具，但也代表公司遞延所得稅資產於未來無法實現的部分，會對公司股價反應造成不利影響；(4)從來源觀點來看，企業在進行盈虧互抵時，若損失後抵項目受到的限制愈多，其價值攸關性會愈小；(5)從租稅觀點來看，虧損扣抵在兩稅合一實施後租稅減免效果並未改變，其對公司價值的增加與兩稅合一前沒有顯著差異。整體而言，投資人對兩稅合一前後所得稅抵減、虧損扣抵及遞延所得稅資產備抵評價對公司價值之影響具有明確認知，並未有「功能性固著」現象發生。

This paper explores whether loss carryforwards can convey value-relevant information to market investors. The results show that, from the measurement perspective, deductible temporary differences and loss carryforwards are regarded as assets and thus have a significant positive impact on stock price. Secondly, from the information perspective, value-relevance of abnormal earnings is smaller for firms with tax carryforwards, indicating that tax carryforwards can create future tax savings effects but it also leads to a higher likelihood of losses in the future. Thirdly, smaller value-relevance of abnormal earnings for firms with valuation allowance indicates that valuation allowance is a useful means for earnings management, but it is perceived as an unrealized portion of deferred tax assets in the future. Fourthly, loss carryforwards are more value-relevant for firms with more loss offset restrictions. Finally, the implementation of the integrated taxes system has not significant effect on tax reduction effect of loss carryforwards, and in turn firm values. In sum, investors can ”see through” the impact of investment tax credit, loss carryforwards, and valuation allowance on firm value after the 1998 Tax Reform in Taiwan; our results thus don't provide supporting evidence on functional fixation hypothesis.