Resumen
In the present paper is studied the relations between the fiscal policy and the indebtedness, in tenns of its viability and macroeconomic sustainability, within the framework of the dynamics of the growth of the country and its restrictions. On the fiscal frame and the structure ofthe indebtec1ness ofthe country, one analyzes the sustainability and vulnerability ofthe national debt from the point of view of the internal and extema1 shocks. The analysis of sustainability of the national debt start of the budgetary restriction of the govemment, evaluating the increase of the coefficient of debt due to the real interest rate, the growth of the economy (effect snow ball) the primary deficit (like proportion ofthe GDP) and the effect stock-flow, which reflects the growth of the coefficient of debt by reasons, such as the devaluation - that it increases the national debt external valued in national currency or by valuations and/or statistical discrepancies.The model it evaluates the objectives ofthe economic policy (income, expenses, deficit or surplus, risk country) in tenns ofthe debt coefficient. The results show how much greater it is the participation of the debt extracted within the total debt, greater the real devaluation will be its vulnerability to changes and in the rate of you cornmit international. The made estimations indicate that an increase in the extema1 interest rate (on its observed levels), marginally make worse the imbalance in the finances of the central govemment. The sostenibility breach does not vary of important way. In terms of the type of change average the results differ since an devaluation, elevates the breach of not sostenibility. The results of the sensitivity analysis a110w to recornmend that it is deepened in the strategy to exchange external debt by internal, in order to reduce this potential source ofinstability in the public finances.