The Night-time Economy: Laurie Taylor talks to Adam Eldridge, Senior Lecturer in Sociology at the University of Westminster, about the origins and changing nature of the after dark economy. They're joined by Emily Nicholls, Senior Lecturer in Sociology at the University of Portsmouth and author of a new, Newcastle based study into the phenomenon of the 'girls night out'. How do young women negotiate friendships, flirtations and fun on a night out with mates? Producer: Jayne Egerton