COMPETITION VERSUS COLLUSION: THE PARALLEL BEHAVIOUR IN THE ABSENCE OF THE SYMETRY ASSUMPTION

Cartel detection is usually viewed as a key task of competition authorities. A special case of cartel is the parallel behaviour in terms of price selling. This type of behaviour is difficult to assess and its analysis has not always conclusive results. For evaluating such behaviour the data available are compared with theoretical values obtained by using a competitive or a collusive model. When different competitive or collusive models are considered, for the simplicity of calculations the economists use the symmetry assumption of costs and quantities produced / sold. This assumption has the disadvantage that the theoretical values obtained may deviate significantly from actual values (the real values on the market), which can sometimes lead to ambiguous results. The present paper analyses the parallel behaviour of economic agents in the absence of the symmetry assumption and study the identification of the model in this conditions.