Designing international environmental agreements : incentive compatible strategies for cost effective cooperation The international character of todays most pressing environmental problems has become a key challenge for environmental policy making. As regulation by a supranational authority is not a realistic option at present policymakers have to rely on decentralized approaches to the management of international environmental resources. This study combines two core dimensions of international environmental policy: the traditional search for cost effective policy instruments and the creation of incentives for voluntary cooperation among sovereign nations. The analysis offers some clear cut policy recommendations for the design of environmental treaties and for the further development of existing international institutions to protect the global environment