企業多角化與股東之間資訊不對稱關係之研究

Corporate Diversification and Information Asymmetry between Investors

本文研究企業從事多角化活動後，公司資訊環境改變，股東間資訊不對稱的影響為何？以及公司系統風險β值及資訊併入股價速度，是否受到企業從事多角化活動影響而改變？進行檢驗時，則加入樣本對照組的研究設計，以排除其他干擾變數影響本研究結果。本文實證結果發現，企業從事多角化活動後，顯著減少投資人之間資訊不對稱，以及顯著降低公司系統風險β值。至於資訊併入股價速度，則沒有顯著改變。研究顯示企業從事多角化活動後，會降低具資訊交易者的活動與私人利益，以及降低公司整體市場系統風險，並減少市場參與者的投資風險。

We examine the effect of information asymmetry when firm’s information environment changed after corporate diversification; meanwhile, we also examine if Beta coefficient and the speed of stock price changing are influenced by corporate diversification. The control group is included in the research design to eliminate the result be influenced by the other moderating variables. We find that information asymmetry and Beta coefficient reduce significantly after the corporate diversification, and there is no significant change on the speed of stock price changing. The result also indicates that corporate diversification can reduce the activity and private benefit of information traders, and reduce firm’s system risk and investor’s risk of investment as well.