EN
The study examines the development of the Polish economy as well as the economies of selected European Union countries in the period from 1949 to 2006. Models based on GDP growth in particular countries were also built. Much space is devoted to a comparative analysis of the development of economies in the countries concerned. A BEKK multivariate GARCH model was built, which allowed for defining a multivariate ARCH effects. Much space is devoted to the theory of the construction of the VECH secondary model and its estimation method. The causality of the impact that economies exert on one another was examined and the occurrence of the multivariate ARCH effect was verified by means of Hosking test.