Regulators act as "market referees", balancing the often-competing interests of stakeholders such as governments, current and future actors in the markets, and consumers. At the same time, markets are rapidly changing due to new technologies, the international drive toward carbon-neutral economies, and, more recently, the COVID-19 pandemic and energy and cost-of-living crises. Continuously assessing the performance of economic regulators is thus important to ensure regulators continue to perform in a changing context.