The aim of our book is to explore theories in the financial literature that clarify the origins, contributions and constraints of earnings management practices, from the angle of several theories, principally agency theory and signal theory.The book clarifies terminology and draws up a typology of accounting manipulations.it proposes an analytical framework that complements the political-contractual model with psychological explanations and highlights the key role of managers.it also focuses on the interaction between incentive effects and monitoring effects on managers' choices regarding accounting manipulations. It concludes with a presentation of models for measuring the quality of accounting statements.