Arguments for increasing gender diversity on corporate boards of directors by gender quotas range from ensuring equal opportunity to improving firm performance. The introduction of gender quotas in a number of countries, mainly in Europe, has increased female representation on boards. Current research does not unambiguously justify gender quotas on grounds of economic efficiency. In many countries, the number of women in top executive positions is limited, and it is not clear from the evidence that quotas lead to a larger pool of female top executives, who, in turn, are the main pipeline for boards of directors. Thus, other supplementary policies may be necessary if politicians want to increase the number of women in senior management positions.