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α: calibrated so average coauthorship-adjusted count equals average raw count
Should organizers of events share the associated costs of maintaining public order? We address this question by using unique data from the Swedish soccer league where co-payment for police were introduced for some clubs only. The difference-in-differences analysis shows that co-payments increased private guards by 40% and suggests a reduction of unruly behavior by 20%. The results are consistent with our model, where co-payments alleviate under-provision in efforts by organizers to combat problems such as hooliganism due to externalities and free-riding on police services. The model also sheds light on the critique that co-payments could lead financially constrained organizers to provide less security.