Book excerpt: Chapters relating to regulatory coherence or cooperation are becoming significant features in new preferential trade agreements, including the Trans-Pacific Partnership (TPP). While the existing literature has considered in detail the potential for harmonisation of standards or institutional cooperation and its impact on the regulatory autonomy of treaty parties, this chapter focuses on those elements of regulatory coherence that relate to domestic processes for the development of regulations. It examines whether the adoption of 'good regulatory practices' in accordance with the TPP will help to ensure that measures states enact to protect non-economic interests (such as the environment or public health) are consistent with other key obligations of international trade and investment law. Although many elements of good regulatory practice mirror the criteria used to distinguish legitimate regulatory measures from disguised protectionism, there is no guarantee that a tribunal will come to the same conclusions as those reached during a domestic regulatory impact assessment.