Book is in French Edited by Jean-Pierre Collin and Mélanie Robertson. In this book, thirteen contributors have tried to portray how metropolitan regions have developed in terms of geographic and institutional organization, how political and institutional settings interrelate with the socio-cultural and economic characteristics of large urban areas and their political processes and public policy, and how various efforts have been made to reform metropolitan institutions. The contributors have profiled the issues through a comparative and interdisciplinary approach to formal institutional arrangements and public policy. In particular, they have analyzed experiments with metropolitan governance and government on four continents, thus offering a fresh look at the political dimensions of the dynamics of metropolitanization. Their analyses show us why and how changes are happening on a metropolitan scale to: 1) the scope of urban political actors for action and their skills in negotiating and thus reinforcing their power; 2) the ways public policy choices are made; and 3) the purposes that the actors assign to institutions. Modern metropolises will become key political actors in the coming years and promise to revitalize the political arena.