In the process of globalization, incentives occupy an increasingly important place on the legal scene. Given the critical importance of taxation systems, fiscal measures have become decisive tools to confer incentives in the different stages of the tax raising-process. Yet the application of tax incentive rules (via such measures as exemptions, credits, deferrals, cancellations, or allowances) remains complex and intricate. Against this background, the regulatory framework of tax incentives, which applies at national levels, derives from two major sources: the law of State aid under EU law and the law of subsidies under WTO law. These two legal systems affect and shape the internal structure of national tax systems. Their adaptation to direct taxation may however be fraught with difficulties. Given that aids and subsidies granted in the form of tax advantages have proliferated over the last decade, it is crucial to investigate whether EU and WTO regulation in this regard is compatible with national tax systems. This ground-breaking book carries out an in-depth analysis of the multi-level regulation of State aid and subsidy in the regulatory context of taxation. Starting from a review of the substantive provisions of tax incentives as provided for in European law and in WTO law, the author moves on to examine how these legal frameworks are enforced at national levels. The book covers practical elements in the following areas:rnrn- legal regimes of State aid and subsidy (including rules on compatibility with the internal market, rn- classification of subsidies and analysis of prohibited subsidies in taxation);rn- definitions of State aid and of subsidy;rn- analysis of the criteria for tax selectivity and specificity;rn- administrative and judicial review;rn- rights of taxpayers as private parties in State aid and subsidy litigations;rn- remedies (including recovery, withdrawal and countervailing duties);rn- overlaps between EU and WTO rules;rn- liabilities in situations of conflict;rn- case-law of the Court and WTO adjudicating bodies.rnrnBy establishing the extent to which EU and WTO regulations of tax incentives affect and shape national tax systems, this book deals with critical issues that have not been addressed hitherto, despite the crucial relevance of the subject and the needs of practitioners to know the relevant rules. It will be of great value to a large group of readers at distinct levels, including lawyers defending State aid and subsidy cases, practitioners, judges, civil servants and scholars in tax law and competition law. Awards: The book was awarded the Grand Prix Solennel de la Chancellerie des Universités de Paris for the best doctoral thesis defended in 2010 and the Award for Outstanding PhD by the Luxembourgish National Research Fund (FNR).rn