Applications such as iMessage, KakaoTalk, LINE, Signal, Skype, Snapchat, Threema, Viber, WhatsApp and WeChat have become an increasingly popular means of personal and business interaction. Surprisingly little academic effort has gone into understanding the nature and origin of these...

Network shares and retail prices are not symmetric in the telecommunications market with multiple bottlenecks which give rise to new questions of access fee regulation. In this paper we consider a model with two types of asymmetry arising from different entry timing, i.e. a larger reputation for...