Book excerpt: Megacities of over 10 million inhabitants are unique entities in their own right, both challenging and supporting the policies, governance and cohesion of states. In developing and developed economies, the rise of megacities can be seen to have negative and positive effects; from exacerbating and deepening societal problems inherent in inequality and poverty, to increasing opportunities for innovation, education, interconnectivity and development.The Rise of Megacities takes a multidisciplinary and interdisciplinary approach to analysis of their growth. It examines both the major new challenges that the expansion of megacities brings for development at large, and the opportunities they might create for the public good. In addition, it shows how more established cities, such as Tokyo, New York or European examples can provide lessons for governance and development of rapidly urbanizing populations. Using case studies and academic theory it takes into account both the similarities and differences of megacities and gives a comprehensive study of them. This book is perfect for students and researchers of development economics, urban studies, international relations and the social sciences, as well as those interested in how the world economy is changing through globalization.