Concentration in the mobile operating systems market
  Concentration phenomena concern the ICT market. Though the regulatory action has been active mainly in the telecom network operators industry, even more significant worldwide concentration phenomena affect other industries. The market of mobile operating systems is analysed through two concentration indices to get a quantitative picture of the current situation and its evolution over time: the Hirschman Herfindahl Index (HHI) and the Four-Firm Concentration Ratio (CR4). A strongly imbalanced oligopoly is shown to exist, where the four major operating systems take over 99% of the market, but the dominant operating system Android alone is installed on over 80% of the new devices. 
Maurizio Naldi
cs.CY