Book excerpt: Health spending continues to grow faster than the economy in most OECD countries. In 2010, the OECD published a study of strategies to increase value for money in health care, in which pay for performance (P4P) was identified as an innovative tool to improve health system efficiency in several OECD countries. However, evidence that P4P increases value for money, boosts quality of processes in health care, or improves health outcomes is limited.This book explores the many questions surrounding P4P such as whether the potential power of P4P has been over-sold, or whether the disappointing results to date are more likely rooted in problems of design and implementation or inadequate monitoring and evaluation. The book also examines the supporting systems and process, in addition to incentives, that are necessary for P4P to improve provider performance and to drive and sustain improvement. The book utilises a substantial set of case studies from 12 OECD countries to shed light on P4P programs in practice.Featuring both high and middle income countries, cases from primary and acute care settings, and a range of both national and pilot programmes, each case study features: Analysis of the design and implementationdecisions, including the role of stakeholders Critical assessment of objectives versus results Examination of the of 'net' impacts, includingpositive spillover effects and unintended consequences The detailed analysis of these 12 case studies together with the rest of this critical text highlight the realities of P4P programs and their potential impact on the performance of health systems in a diversity of settings. As a result, this book provides critical insights into the experience to date with P4P and how this tool may be better leveraged to improve health system performance and accountability. This title is in the European Observatory on Health Systems and Policies Series.