Board size and corporate performance: the missing role of board leadership structure

Different arguments have been introduced in the literature both for and against large and small board sizes. In this context, empirical evidence regarding the impact of board size on corporate performance is less conclusive, which means that further study is needed. Contrary to previous work, it is hypothesized in this study that the relationship between board size and corporate performance is more likely to be confounded by board leadership structure. Econometric analysis provided strong evidence for the applicability of this hypothesis and demonstrated that board size positively affects corporate performance in the presence of CEO non-duality (board leadership structure that is split between the roles of the CEO and the roles of the chairman). Furthermore, board size is shown to have a negative influence on corporate performance in the presence of CEO duality (board leadership structure that assigns the roles of both CEO and chairman to the same person). This conclusion is robust to the use of different measures of corporate performance, control variables and econometric models. Thus, these findings cast doubt on most of the existing evidence that posits that either large or small board size is always the best alternative to be followed in all organizations.