This Final Report is submitted for the implementation of specific contract No EAC/2012/0615 "Study on the effective use of early childhood education and care (ECEC) in preventing early school leaving (ESL)". The study is carried out by the Public Policy and Management Institute. The aim of the study is to get a better understanding of the evidence base behind the relationship between good-quality early childhood education and care and early school leaving rates and to support the work of the European Commission and Member States, within the Strategic framework Education and Training 2020. Specific objectives of the study include: development of a state of the art conceptual framework for analysis, reviewing existing research across Europe and beyond (all previous research that is available in European languages --most importantly longitudinal); collecting new data and analysing relevant policies and their effects across Europe; providing recommendations for actions that could be taken at European and national level to improve the effectiveness of ECEC services, to promote ECEC and to contribute to the development of a more comprehensive approach to tackling underachievement and early school leaving. The report presents the final results of the assignment and the methodology that was used to complete it. (author abstract)