Pré-publication, Document de travail: Hosting the Olympic Games costs billions of taxpayer dollars. Following a quasi- experimental setting, this paper assesses the intangible impact of the London 2012 Olympics, using a novel panel of 26,000 residents in London, Paris, and Berlin during the summers of 2011, 2012, and 2013. We show that hosting the Olympics increases subjective well-being of the host city's residents during the event, particularly around the times of the opening and closing ceremonies. However, we do not _nd much evi- dence for legacy e_ects. Estimating residents' implicit willingness-to-pay for the event, we do not _nd that it was worth it for London alone, but a modest wellbeing impact on the rest of the country would make hosting worth the costs.