本研究主要是探討台灣企業在海外上市後對於原股之影響，並從三個角度去做觀察，分別是價格效果、流動性效果以及風險效果。選擇的樣本是從1992-2006期間同時在台灣與國外上市的台灣企業。
研究問題與方法：
1. 價格效果是以事件研究法之市場模式計算宣告海外上市對公司價值之影響，並將樣本分為電子與非電子產業、以子公司與發行DR方式進行分類探討，接者使用迴歸模型去分析影響累積異常報酬的因素。
2. 流動性效果是以交易量為依據，計算海外上市前後的流動性是否發生改變。
3. 風險效果是以Beta值為依據，計算海外上市前後的原股風險是否發生改變。
實證研究結果顯示：
1. 宣告海外上市當日出現正向顯著的異常報酬，而上市後五天的累積異常報酬增加幅度最快，之後則趨於緩和。影響海外上市的因素以上市地點及匯率有顯著效果，相較於在美國與香港，在歐洲上市的效果較為顯著，而匯率的部份與過去文獻一致，本國貨幣貶值的確會造成正向異常報酬。非電子產業的宣告效果優於電子產業，以子公司方式進行海外上市的企業其宣告效果優於以DR方式進行海外上市的企業。
2. 海外上市後的流動性呈現顯著的提升。
3. 海外上市後的風險值呈現顯著的下降。

This article examines the impact of international cross-listings on local stock exchanges by focusing on the experience of Taiwan and the impact includes the price effect, liquidity effect and risk effect. The sample consists of 58 firms that dual listed over the period 1992-2006.
First, during the 30 days after the day of announcement, the average cumulative abnormal return rises significantly by over 2 and rises by over 0.5 around the inter-listing date. Second, the price effect is related to the choice of geographical location, industry type and the approach for issuing equity abroad. Third, the liquidity (trade volume) of the domestic stocks increased after cross-listings. Fourth, the risk (beta) of the domestic stocks decreases after cross-listings. Finally, our findings support the hypotheses of information content, market segmentation, liquidity and risk.

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參考資料：
1. 行政院金融監督管理委員會證券期貨局
http://www.sfb.gov.tw/intro_index.asp
2. 香港交易所
http://www.hkex.com.hk/index.htm
3. 華爾街日報online
http://chinese.wsj.com/big5/index.asp
4. 經濟新報資料庫
5. 公開資訊觀測站