本研究採用事件研究法，檢視2001年1月至2003年6月間，上市櫃公司實施減資之效果。以瞭解減資來彌補虧損及實施庫藏股並辦理減資等兩類減資形式，是否存在異常報酬。結果發現，依公司法減資以彌補虧損的企業，長期投資績效呈現負的平均異常報酬，但統計上的顯著性，並未獲得一致結論；依證交法實施庫藏股減資的企業，由全部樣本觀察，長期投資績效似乎不存在長期平均異常報酬。不過，與依公司法減資之公司結果相比較，有較佳之長期平均績效。
In order to identify the effects of price behavior by reducing capital to make up a lose and stock repurchases, the investment performance of listed firms from January 1, 2001 to June 30, 2003 are examined by event study. It is indicated that capital decrease according to Corporate Regulation to make up a loss are associated with negative return but not significantly. On the other hand, the long-term investment performances of capital reducing firms according to Security Transaction Regulations do not show abnormal returns. However, the performances of capital reducing firms according to Security Transaction Regulation are better than those according to Corporate Regulation.
