This report examines the impact of policy interdependence on how governments regulate. It has two purposes. The first is to understand better the dynamics of thc emerging multi-governmental regulatory system, and the relationships, institutions, and processes that comprise its working parts. The second is to suggest practical approaches by which national governments can establish solid managerial and administrative foundations for regulatory co-operation, within thc constraints of democratic and open government. The chapters in the report are based on papers prepared for an OECD Symposium on ‘‘Managing Regulatory Relations Between Levels of Government” held in October 1993, and on discussions at the Symposium.