Pension funds and sovereign-wealth funds own a large and increasing fraction of the shares in publicly traded companies in the OECD area. These funds typically have a very long time horizon on their investments, as well as highly diversified portfolios. These features imply that the interests of these funds on important issues are aligned with the interest of future generations because the long-term return on a highly diversified portfolio will depend on the degree to which the development of the world economy is sustainable. It is, therefore, in the enlightened self-interest of these investors to use their shareholder rights so as to protect the interest of future generations. The paper explores the arguments for a more active corporate governance policy among pension funds and sovereign-wealth funds and discusses the obstacles to such policies.