<P>The 22 papers in this volume illustrate the itinerary of Henry Tulkens on the occasion of his retirement from teaching. The volume presents contemporary analysis of Tulkens’ classic papers on public sector economics. The collection is structured in four parts: I. Decentralized resource allocation processes for public and private goods - II. Environment, public goods and externalities - III. Efficiency analysis - IV. Fiscal competition and optimality.</P>