Corporate governance and game theoretic analyses of shareholder power: the case of Spain

The definition and implementation of control is at the heart of the corporate governance debate. The paper approaches the issue by using power indices derived from the theory of cooperative games. An application to Spanish listed firms shows that incentives for large shareholders to form controlling blocs are high. In the Spanish system of corporate governance ownership concentration is therefore the main mechanism to mitigate agency problems between shareholders and managers. Moreover, these results suggest that the Shapley–Shubik index is not an appropriate measure of shareholder power.