CEO DUALITY AND FIRM PERFORMANCE: WHAT'S THE FUSS?
研究了CEO兼任董事长（两职合一）与企业绩效的关系，发现市场对两职状态变化反应平淡，运营绩效变化不明显，长期绩效影响微弱。
Rising shareholder activism following poor corporate performance and a subsequent drop in shareholder value at many major U.S. corporations had rekindled interest in duality and corporate governance. Despite limited empirical evidence, duality (chairman of the board and CEO are the same individual) has been blamed, in many cases, for the poor performance, and failure of firms to adapt to a changing environment. In examining the relationship between duality and firm performance, this study considers the announcement effects of changes in duality status, accounting measures of operating performance for firms that have changed their duality structure, and long-term measures of performance for firms that have had a consistent history of a duality structure. Our results suggest that: (1) the market is indifferent to changes in a firm's duality status; (2) there is little evidence of operating performance changes around changes in duality status; and (3) there is only weak evidence that duality status affects long-term performance, after controlling for other factors that might impact that performance.