Abstrakt:
Anticompetitive horizontal behaviors are very common and harmful for economy as a whole and consumer welfare especially. Such behaviors in most cases mean collusion. Pro-active anticompetitive policy we want to realize implies monitoring of huge set of markets and industries. As preliminary selection is possible on a basis of number of factors that enhanced collusion, there could be still big set of industries left. There is a necessity then for methods of collusion’s detection which would be quick, resource — saving and understandable for economists, experts and lawyers without quantitative experience. We described here fairly simple but meaningful, graphical tools which could be used in process of screening for collusive behavior in the markets. We underlined that ability of graphical inspection depends on statistical/econometric tool of choice for particular screen, so we see a need for research and popularization of tools with that property.