The World Bank convened a global conference in April 2000, to address the benefits and challenges of investing in early childhood development. The fact is that 125 million primary-school age children are not in school; another 150 million children drop out of primary school before they complete four years of education; and almost one-half of the children in the least developed countries of the world do not have access to primary education. With the publication of this volume, which contains the conference proceedings, the World Bank hopes to encourage a broader investment by countries, companies, organisations and private sector institutions in early child development. The book is in five sections: the benefits of investing in the young; measuring the early opportunity gap; evaluating the effectiveness of early childhood programmes; the private sectors influence on the public sector; investing in the future - action and policy.