Artificial intelligence is rapidly transforming economies and societies, but research on how it is being adopted across firms is still in its early stages, especially at the international level. This column explores the patterns of AI use across 11 countries, focusing on firm characteristics, the role of complementary assets, and the links between AI use and productivity. Evidence of polarised adoption – with larger and more productive firms more likely to use AI – indicates the potential for widening gaps between leaders and other firms and reinforces the need for policies aimed at fostering an inclusive digital transformation. https://cepr.org/voxeu/columns/firms-use-artificial-intelligence-cross-count... Luigi