Charles Calomiris talks to Romesh Vaitilingam about his recent book, co-authored with Stephen Haber, ‘Fragile by Design: The Political Origins of Banking Crises and Scarce Credit’. They discuss how politics inevitably intrudes into bank regulation and why banking systems are unstable in some countries but not in others. Calomiris also presents his analysis of the political and banking history of the UK and how the well-being of banking systems depends on complex bargains and coalitions between politicians, bankers and other stakeholders. The interview was recorded in London in February 2014.