In the last decades a growing awareness emerged of the relevance of corruption as an hidden factor which may negatively affect political and economic decision-making processes. In spite of a lively scientific debate there is no general consensus on a commonly accepted definition of what corruption is.The A. distinguishes three main paradigms, focusing on different (though not irreconcilable) variables.The first is the economic paradigm, which usually takes the principal-agent model of corruption as its founding pillar. In this paradigm corruption is considered the outcome of rational individual choices, and its spread within a certain organization is influenced by the factors defining the structure of expected costs and rewards.A second app...