  An important issue within the present economic crisis is understanding the
dynamics of the public debt of a given country, and how the behavior of average
consumers and tax payers in that country affects it. Starting from a model of
the average consumer behavior introduced earlier by the authors, we propose a
simple model to quantitatively address this issue. The model is then studied
and analytically solved under some reasonable simplifying assumptions. In this
way we obtain a condition under which the public debt steadily decreases.
