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...

In 2000, there were as many countries served by a single mobile network as by network competition. Today, only 30 countries, representing less than 3% of the world’s population, are served by a single network. There has been considerable discussion about the optimal number of network operators...