Title: How to model fake news,
Abstract: Over the past three years it has become evident that fake news is a danger to
democracy. However, until now there has been no clear understanding of how to
define fake news, much less how to model it. This paper addresses both these
issues. A definition of fake news is given, and two approaches for the
modelling of fake news and its impact in elections and referendums are
introduced. The first approach, based on the idea of a representative voter, is
shown to be suitable to obtain a qualitative understanding of phenomena
associated with fake news at a macroscopic level. The second approach, based on
the idea of an election microstructure, describes the collective behaviour of
the electorate by modelling the preferences of individual voters. It is shown
through a simulation study that the mere knowledge that pieces of fake news may
be in circulation goes a long way towards mitigating the impact of fake news.