Cohesion policy remains a contentious topic in the EU, central as it is to the matter of convergence between regions. The need to share economic growth throughout the bloc is particularly acute in the wake of notable electoral advances from several more populist political parties in Europe in recent years.Bruegel senior fellow Zsolt Darvas explains how his recent study, co-written with Jan Mazza and Catarina Midões, adopts a new methodology with the aim of avoiding the complicating factors that have underpinned the greatly varied results of many previous assessments of cohesion-policy effectiveness. He explains further how the EU might refine its implementation of cohesion policy, and looks ahead to what might be the biggest obstacles to improvement.For further reading, we recommend the Bruegel Policy Contribution at the centre of this Deep Focus episode, ‘How to improve European Union cohesion policy for the next decade’.