Timing and Wealth Effects of German Dual Class Stock Unifications
研究1990-2001年间德国双重股权公司转为单一股权的原因与成本，发现公告日公司价值平均上升4%，且所有权结构与流动性变化能解释异常回报的差异。
Abstract This paper studies the reasons and the costs of separating ownership from control by analysing the decision of German dual class firms to consolidate their share structure from dual to single class equity between 1990 and 2001. We find that the firm value increases significantly by an average 4% on the announcement day. A significant part of the variation in abnormal returns can be explained by the ownership structure and by changes in liquidity. A logit analysis of the unification decision yields that firms are more likely to unify if their controlling shareholder loses only little voting power in a stock unification. Also, firms that are financially constrained are more likely to abolish dual class shares; these firms often issue additional shares after the stock unification.