In this paper, we derive conditions under which the simple majority voting rule for electing controlling management and one share-one vote constitute a socially optimal corporate governance rule. We also show that other majority rules and/or multiple classes of shares are not socially optimal. Finally we show that an entrepreneur would choose to issue two securities, one with only cash flow claims and no votes and one with only votes and no cash flow claims, if this were allowed. This scheme, regardless of the majority rule adopted, is not socially optimal.