Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Using euro conversion as the trigger, we examine what drives volume and spread changes when stock exchanges compete. Results show average trading costs on European exchanges decrease almost 9%, and turnover increases over 30%. Trading costs decline or remain unchanged on all exchanges, but volume deteriorates in some markets and improves in others. Frankfurt, Paris, London, and Milan are winners, while Madrid and Brussels lose volume. We examine the role of the spread-volume relation, firm characteristics, exchange trading rules, and country-level factors in determining these outcomes. Results suggest that euro conversion prompted competition by increasing transparency in market prices.