This paper provides empirical evidence about the determinants of corporate ownership structure. In Swedish listed corporations, ownership concentration decreases with firm size and increases with firm-specific risk. We also find that dual classes of shares create vote concentration but that the presence of differential voting rights have limited impact on equity concentration. Our results indicate that the ambition to control a firm is not motivated by a 'pure demand for power'. Furthermore, the value of control does not derive from the possibility to expropriate the fringe of minority shareholders. The value of control has to be motivated by some other economic motives including ownership of equity. © 1990.