'This wonderful book illuminates, entertains, explains and demystifies that most essential but rarely-understood entity, money. Above all, it demonstrates the link between money and the capacity of the state to tackle any collective problems: money fundamentally matters and so, therefore, do its minders in central banks. This book describes how central bankers think about their task, what models and evidence they use to make decisions about interest rates and other tools at their disposal - and also sets out how they should think about it.' Diane Coyle, University of Cambridge