The growth of shareholder value has been a major change in Western economies since the 1980s. This growth has reignited debates concerning relations between investors and managers. This book argues that investors are more than passive providers of finance, on whose behalf managers seek to maximize shareholder returns. Instead, many investors directly influence management practice, through investor engagement. The book examines the role of institutional investors and private equity firms, two types of investors with overlapping but different reasons for engagement. Questions addressed include: What are the incentives, and disincentives, for investment engagement? How is investor engagement organized? What areas of management practice are of particular concern to investors? The discussion shows in detail how private equity firms play a major role in developing new companies, beyond the provision of finance, especially in the IT, biotechnology, and pharmaceutical sectors. The discussion is primarily based on British and US research. The debate has wider international relevance, because there are strong pressures for establishing shareholder value as the international 'norm' for systems of corporate governance. Following a detailed discussion of Germany, the authors conclude that there is no inevitable trend to shareholder value: shareholder value depends upon complementary institutional arrangements in national business systems, which are far from universal. The book concludes with a critical analysis of the justifications for shareholder value and investor engagement, highlighting the weaknesses of both efficiency and equity justifications.