In order to ensure transparency and competition in public procurement markets, OECD member countries have made themselves subject to a degree of regulation, both through competition policy generally and through specific laws related to public procurement. Such measures can place restrictions on the "scope" for including environmental criteria in their procurement practices. In many cases, such constraints mirror obligations agreed to through adherence to international procurement regimes, such as those discussed in the previous chapter. However, in other cases, there can be important differences...