It would be fair to say that foreign aid today is one of the most important factors in international relations and in the national economy of many countries – as well as one of the most researched fields in economics. Although much has been written on the subject of foreign aid, this book contributes by taking stock of knowledge in the field, with chapters summarizing long-standing debates as well as the latest advances. Several contributions provide new analytical insights or empirical evidence on different aspects of aid. As a whole, the book demonstrate how researchers have dealt with increasingly complex issues over time – both theoretical and empirical – on the allocation, impact, and efficacy of aid, with aid policies placed at the center of the discussion.