By comparing the tax incentive systems of 26 different nations, this report – the third in the Future World Giving series – attempts to develop a more holistic understanding of the efficacy of different approaches. Unlike other studies of tax incentives for giving, this report attempts to put tax incentives in the wider policy context. In doing so, we consider not only the value of incentives but also how that value differs for different donors, what causes are incentivised and how accessible incentives are. Building on Rules to Give By – a report we produced with Nexus and McDermott Will & Emery that looks at the basic legal environment for giving in all 193 UN recognised nations – this report looks in depth not only at the availability and value of tax incentives for giving but also considers the political justifications for those incentives, the range of causes available to donors and the fairness of the system as a whole.