This text introduces and assesses the principles and theories underlying changes in the scope and management of the public sector. The earlier, traditional model of public administration dominant for most of the 20th century is argued to be discredited. Newer public management models are being adopted all over the world and the basis, nature and dimensions of these as well as their theoretical underpinnings are considered in detail. The second edition of this text is revised and updated throughout with the addition of a new chapter on public management in developing countries.