Malware and market share: a comment on Arce

Arce (Malware and market share. J Cybersecur 2018;4:tyy010) presents a game-theoretic model in which users select and hackers target one of two IT platforms based upon the platforms’ network benefits and security levels. Unfortunately, in modelling the network benefits, Arce misinterprets Metcalfe’s law. In particular, he assumes that the utility that a user obtains from a platform increases quadratically with the number of users, whereas Metcalfe’s law holds that utility increases linearly with network size.