The issue of optimal size of the general government sector is analyzed by researchers using various
methods, most often through the prism of a specific goal. The article is an attempt to determine the optimal size
of the general government sector from the perspective of EU economies. To achieve this goal, the innovative
decision tree technique - the c5.0 method was used. The study covered data describing 28 EU member states in
the years 2000-2017 and 16,632 input data were analyzed.
The results of the conducted research showed that despite the fact that there is no single optimal and universal
solution, a series of dependencies can be observed. Knowing the impact of individual actions on the economy,
you can choose such instruments, as well as such a configuration that will help in a given area without harming
others. Thus, the technique used, combined with specific priorities in terms of impact on the economy, may
show which values of specific variables in the general government sector level should be pursued in order to
model the desired effect.