Power laws in economics and/or finance

In this work, we introduce the notion of power law and study its properties. We also discuss various statistical methods used to determine the presence of power laws and we illustrate those techniques using the data related to Belgian city and town population in 2000. Furthermore, we look at procedures from which power laws may arise. In particular, we focus on two methods: the preferential attachment model, that refers to a process in which a discrete number of objects is randomly added to a set of containers, and the percolation process, that is a mechanism revolving around finding a critical value at which a dynamical system suddenly shifts from a convergent state to an exploding state.Master [60] en sciences économiques, orientation générale, Université catholique de Louvain, 201