強制性預測資訊的有用性一直備受爭議。一項預測資訊是否有用，取決於預測差 之大小，即當預測準確度增加，對使用者有用性亦增。本研究即在探討強制性揭露制度下， 管理者所作財務預測準確度有關之影響因素，研究樣本為證管會規定須作強制性揭露公告預 測之上市公司。研究結果顯示，未預期經濟變動、上市期間、預測高低估及規模（總資產） 成長率能解釋營業益預測約20％變異；而未預期經濟變動、規模（營業額）成長率、上市期 間及稅前盈餘變動性則為影響稅前損益預測準確度之四個主要變數。本研究亦進一步探討規 模增額，得知新投資資金來源之股東權益部分與預測準確度有顯著相關。

　　　　　Mandatory disclosure of management forecasts is disputable because the accuracy of forecasts is affected by many factors. This research tries to explore ten variables that influence the accuracy of management forecasts of operating profits and earnings before taxes. Using disclosure data from companies that are on the security market, the research results showed that unexpected economic change, list period, conservation approach and scale (assets) growth rate are four main variables that can explain over 20% estimate error of operating profit forecasts. As to the forecast accuracy of earnings before tax, the four influencing variables are unexpected economic change, scale (sales) growth rate, list period and earning volatility. In addition, stockholders'equity as main sources to support new investment will influence the accuracy of forecasts.