Intertemporal budget constraint and public debt sustainability: the case of Italy

The theory of intertemporal budget constraint is applied to test Italian public debt sustainability, with the finding that current fiscal policy has not been following a sustainable path in the 1980s. In particular, we find that (i) while primary surplus is stationary, public debt is not, (ii) permanent shocks explain about 90% of forecast error variance of public debt, while playing a minor role in primary surplus and (iii) debt is not sustainable even if stochastic discount rates are accounted for.