EN
The paper presents the results of an empirical analysis of the stability of taxpayers' income paying in one of the Silesian tax offices. To assess the degree of income stability the Author used Markov chains. Transition probability matrix was constructed, which was used to estimate the synthetic indicator of income stability. The analysis found that the income of taxpayers were characterized by a low degree of stability. The research stated that the probability of transition to a higher income group was lower than the probability of transition to a lower income group, and with the increase in the level of income generated, the probability of transition to a lower or higher income group decreased. The Author proposed a growth measure of the income inequality distribution based on the ratio oftransition probabilities in two extreme income groups. (original abstract)