In recent years, the application of statistical and econometrical techniques in competition economics has increased. One method, for example, is the multiple regression analysis. This is only one statistical tool that covers the effects of factors that influence results and quantifies them. To verify the causal effects of each factor it is necessary to determine all price explaining factors. Statistical tests provide information about stability, robustness, and suitability of the model. These models are used for the estimation of demand elasticities, price forecasts, market definitions, and modelling of mergers.