This paper evaluates alternative strategic models of competition and market structure in online retailing, and makes comparisons with traditional retailing. Online consumers are less concerned than traditional consumers about spatial characteristics and more concerned about hidden quality...

Firms selling multiple quality-differentiated products frequently alter their product lines when a competitor enters the market. We present a model of multiproduct monopoly and duopoly using a general `upgrades` approach that yields a powerful analytical framework. We provide a simple...

We present a general Cournot model in which each firm may sell multiple quality-differentiated products. We use an upgrades approach, working not with the actual products, but instead with upgrades from one quality to the next. The properties of single-product Cournot models carry over to the...

Expansion in mobile phone coverage has improved access to information throughout the developing world, particularly within sub-Saharan Africa.  The existing evidence suggests that information technology has improved market efficiency and reduced consumer prices for certain commodities.  There...

We report the short-term results from a randomized evaluation of a mobile phone literacy and numeracy program (Project ABC) in Niger, in which adult literacy students learned how to use mobile phones as part of a literacy and numeracy class.  Students in ABC villages showed substantial gains in...