Inspired by The Metric Tide report (2015) on the role of metrics in research assessment and management, and Lord Nicholas Stern's report Building on Success and Learning from Experience (2016), which deals with criticisms of REF2014 and gives advice for a redesign of REF2021, this article discusses the possible implications for other countries. It also contributes to the discussion of the future of the REF by taking an international perspective. The article offers a framework for understanding differences in the motivations and designs of performance-based research funding systems (PRFS) across countries. It also shows that a basis for mutual learning among countries is more needed than a formulation of best practice, thereby both contributing to and correcting the international outlook in The Metric Tide report and its supplementary Literature Review.