This volume addresses developments in the theory of fiscal federalism, and insights from the ‘second generation’ models, but also the changes in practice. The latter includes the key multilevel issues that would be relevant in designing and implementing sub-national taxes, budget systems, management of liabilities and macroeconomic stability. In addition it is useful to focus on special issues related to the poor and marginalized, addressing structural change and the environment including facing natural disasters, as well as overcoming conflicts and keeping countries together. The first part of the volume addresses theoretical developments in a historical context – as often theory follows changes in practice. The second part addresses the nexus between policies, instruments and institutions. And the final part addresses key emerging issues in relation to multilevel finance.