How can the successful development of some former Third World countries be explained, while other developing countries have remained stagnant or worse, have deteriorated into failed states? This book offers a history of thought perspective on development economics and an assessment of development aid and cooperation. De Haan examines how the right mix of policies and evolving insights in development economics have impacted certain countries with the progression from low-income to middle-income, while it is still difficult to shift from the middle-income to higher-middle income stage. Does foreign aid work? Due attention is given to aid philosophies since the end of WW2 and how (in)effective the implementation of such philosophies have been. With case studies drawn from the author's own 40 years' experience in development aid, this book is important reading for researchers and students of development economics, development studies, international trade and foreign aid.