“…2 Byers et al (2012a) study the dynamics of discount voucher sales as well as the impact of voucher coupon use on Yelp ratings. 3 A large theoretical literature has explored the mechanisms for "group buying," also known as "social discounting," in which a certain minimum number of consumers must agree to purchase before a deal becomes effective (see, e.g., Che and Gale (1997), Anand and Aron (2003), Jing andXie (2011), Subramanian (2012), Meir et al (2013), Hu et al (2013), Liang et al (2014), andSurasvadi et al (2014)). …”