This volume is the product of the OECD’s Network on Fiscal Relations across Levels of Government, founded in 2003. The Network is a unique high-level body at the OECD that “horizontally” brings together the expertise of multiple fields and four substantive departments – the Centre for Tax Policy and Administration (CTP), the Economics Department (ECO), the Public Governance Directorate (GOV) and the Centre for Entrepreneurship, SMEs, Regions and Cities (CFE) – as well as their principal committees (the CFA, EDRC, EPC, PBO, SBO and RDPC). The Network, chaired by Junghun Kim of Korea, addresses a wide range of challenges for intergovernmental fiscal relations, whether macroeconomic, structural and administrative, and seeks to contribute to stronger, fairer and more stable economies as well as improving the well-being of citizens.