由承銷價低估、市價高估與股權結構觀點分析最適適股策略與IPO折價

THE OPTIMAL IPO STRATEGY AND IPO DISCOUNT: A NEW PERSPECTIVE FROM UNDERPRICING OVERREACTION AND OWNERSHIP STRUCTURE

本文主要的貢獻有二：一是將Ma（1999）對於折價除了考量承銷價低估外，尚須檢視市價高估的論點予以模式化。二是將股權結構與IPO折價結合，探討公司最適之釋股決策。以往有關於IPO折價之文獻，大都將討論重心放在承銷價格被低估，而忽略了折價也可能源於市場過度反應所形成之上市價格高估，因此本文嘗試將傳統的折價分成這兩個層面來討論，以求能更細膩地解析初次公開發行折價的問題，並釐清文獻中折價討論之部分爭議。此外，雖然有愈來愈多的文獻開始將股權結構與IPO折價結合，並將折價歸因於公司價值提昇或控制權之掌控，然而他們尚未深入地探討各變數之影響分析。模型的重要結果如下：首先，我們確認了「擇時發行」應該是發行公司重要的決策問題，這樣的結果也合理解釋了IPO折價跨期波動的現象。我們也發現股權結構與市場景氣並非如Bolton and Thadden（1998）所主張的為一單純地線性關係。此外，低品質公司往往趁著市場景氣熱絡，於IPO大量釋股；但高品質公司則反其道而行。創設股東傾向於選擇資本市場相對樂觀的環境進行IPO釋股。而具有未來性的新興產業，IPO釋股將是募資的最佳手段。最後，認購訊號愈多，愈容易造成投資人盲目認購，產生追價風潮效果。

Two principal contributions were obtained from this study. First, we tried to model the views suggested by Ma (1999), on the IPO discount being affected not only by undervaluing the offer price but also by overvaluing the market price. Second, we investigated the optimal issue strategy through combining the ownership structure with the IPO discount. There has been much previous literature about the IPO discount which discusses the offer price being undervalued. However, the market price can also be overvalued due to the market overreaction. In this study, we attempted to distinguish these two points from the traditional IPO discount. We expect to clarify more about both the IPO discount and the debate on it. In addition, although more and more studies discussed the combination of the IPO discount and the ownership structure, and attributed the IPO discount to the firm’s value or controlling interest, a complete analysis was not provided. Our model confirmed that the IPO timing should be the key issue considered by the issuing firm, which can reasonably explain the fluctuations in underpricing over time. It also showed that the relationship between the ownership structure and the prosperity of the market is not a linear function as what Bolton and Thadden (1998) have claimed. Moreover, a firm with low quality preferred to increase the amount of shares issued during IPO when the market is booming; the high quality one, on the contrary, did not do this. The entrepreneur tended to issue shares in IPO when the market is booming; however, for the newly potential enterprises, issuing shares was the best way to raise funds. Finally, the more the phenomena of subscription, the more the investors subscribe blindly and generate a cascade effect.