In 2004 IOM launched a policy research series on interstate cooperation on migration in order to address this gap in research. With the generous support of the Swiss Foundation for Population, Migration and Environment, IOM commissioned five research papers for presentation at the Second Conference of the Berne Initiative in Berne, December 2004. Four of the five papers examine current forms of interstate cooperation in the field of migration in Europe and Central Asia, Asia, the Americas and Africa, while the fifth paper discusses the trends in interstate cooperation at the global level. Taking as their point of departure the rapid growth in informal non-binding regional consultative processes on migration, the papers analyse their modes of operation, review their outcomes and provide an assessment of their effectiveness in facilitating interstate cooperation at the regional and global level. The papers also suggest ways in which interstate cooperation at the regional and global level might be enhanced in the future.