More than 86,000 football fans passed through Kai Tak Stadium over two nights recently as Manchester City faced Inter Milan and Chelsea took on Juventus. Supporters filled nearby malls and restaurants, with some merchants reporting foot traffic three to four times higher than usual.For those few hours, Kai Tak offered a glimpse of what Hong Kong’s day-to-night economy could become: international visitors and local residents arriving early and extending the occasion beyond the stadium.The...