It is often argued that corporate sustainability requires a corporation to make a profit, to act in a socially responsible manner and to engage in policies that are environmentally sustainable. This is sometimes called the corporation’s triple bottom line. In this paper it is argued that in practice profitability or more general maintaining economic variability constitutes a corporation’s bottom line and that it is limited by this consideration in showing social responsibility and in acting with environmental responsibility. Because of the nature of market competition, it is argued that government intervention is often required to ensure that corporations act in a socially responsible and environmentally acceptable way. In fact, such intervention is absolutely essential in some circumstances for ensuring the sustainability of markets and corporations themselves that want to act in a socially responsible and environmentally favourable manner.