2008年底面對十號公報是否要如期實施，讓產、官之間持續爭論不休。儘管採用10號公報不影響公司現金流量，但卻讓存貨狀況於財務報表清楚呈現，投資人得以藉由預期存貨狀況對企業獲利之衝擊，重新評估公司價值，因此在主管機關與企業界相互角力的過程中，投資人如何看待此事件，頗值得作進一步探討。本研究採用事件研究法，探討十號公報如期實施的宣告是否影響投資人對公司的評價。本研究之實證結果顯示，金管會公佈如期實施10號公報對於高存貨且跌價快的電子製造業確實於事件期產生顯著為負之異常報酬率與累積異常報酬率。其次，我們發現鋼鐵業並沒有如外界所推測的受到嚴重的衝擊，可能是許多企業預期公報即將實行已提前提列損失，減緩了突然的衝擊，最後在公司特性對累積異常報酬率之影響方面，只有存貨數量與累積異常報酬率有顯著負相關，顯示投資人預期存貨較少的企業較不受到10號公報的負面衝擊。值得一提的是，從電子業與鋼鐵業的累績異常報酬分析中可以發現，公報宣告效果僅在事件日前後一天的期間內顯著，於事件日三天後此效果即消失，隱含此事件或許只是投資者一時不理性的反應造成企業價值低估，於短期內股價就迅速回到企業應有的合理價值，這或許可以提供一部份解釋原因說明何以金管會在當時經濟環境一片低迷的背景下仍選擇如期實施此公報。

On December 18 2008, FSC (Financial Supervisory Commission) Minister Sean Chen declared that the Accounting Bulletin No. 10 will take effect from January 1 2009. A fierce debate arises between FSC and private sectors on whether to implement the accounting principle during financial crisis. Even though principles of Bulletin No. 10 will not change firms' future cash flow, investors might still re-evaluate the firms' value since more information about the firms' inventory policy will be revealed. Therefore, we explore in this article how investors response to the enforcement of new accounting principle during such a great depression. We use event study as our methodology and find significant negative impact on Hi-Tech industry and on firms with high inventory stock. However, the impact on the steel industry is not as significant as we expected. We posit that the trivial impact resulted from that most firms in the steel industry have recognized the possible losses complying with the new regulation when expect that the regulation will come to effective. Moreover, the event impact is short-run ï the abnormal return rapidly reverts to zero 3 days after the event day, implying that the impact may be caused by short-run investorsð irrational behavior. This might partly explain why FSC insists to impose the regulation as planned even the financial crisis remains harsh.