Since the beginning of XXI century, market instruments dominate environmental policies. These instruments are inspired by Ronald Coase’s theory; whereby environmental objectives can be translated into obligations or property rights that can be exchanged between economic actors. Assumed to be more effective than command and control regulation by the neoclassic theory, these instruments are supporting policies combating climate change (EU Emission Trading Scheme and Clean Development Mechanism), developing renewable energy (Green Certificates) and reducing energy consumption (White Certificates). But numerous studies highlight unexpected effects and document the adaptation of some of these instruments to local political and technical configurations, or in certain case, the replacement of these instruments by direct subsidies. Relaying on existing studies and original investigation, this communication explains how market-based instruments have lost political acceptance and were contested for efficiency and distributional issues. While these instruments have all been designed with the principle of global commensurability, their implementation was limited or it led to a segmentation of projects, that defeats this principle. It is not a marginal adjustment, but a political and administrative process of policy-practice decoupling.