EN
The aim of the article is to identify the determinants of changes in public debt ratios in the developed countries of the EU (EU-15). The analysis was based on the observations of the average values of analysed variables in particular countries throughout the study period and over two sub-periods: 2001-2007 and 2008-2014. On the basis of the article it can be concluded that the diversification of changes in public debt ratios resulted mainly from varying budget and primary balances (the lower the deficits, the lower the increases in public debt ratios) and, to a smaller extent, also from varying interest rates on bonds (the lower the interest rates, the lower the increases in public debt ratios) as well as varying economic growth rates (the higher the economic growth rates, the lower the rises in public debt ratios).