The relative novelty of the international investment regime has led authors to draw analogies with a range of other systems, from international commercial arbitration to human rights law, in order to respond to the host of theoretical and practical challenges the regime poses. Of these analogies, perhaps the most interesting is the parallel drawn with domestic public law. Advocates of the analogy argue that investment disputes are ‘regulatory dispute[s] arising between the state (acting in a public capacity) and an individual who is subject to the exercise of public authority by the state’ in much the same way as public and administrative law disputes relate to the exercise of public authority in domestic legal systems. They contend that this functional similarity means that it is beneficial to look to domestic public law to fill gaps, resolve ambiguities or understand the nature of the international investment regime.