While there is ample evidence on the linkage between public debt and economic growth for national economies, far fewer investigations have been carried out at the subnational level. In this paper, we therefore study the long- and short-term relationship between regional public debt intensities and economic output (growth) for German federal states between 1970 and 2010. We estimate dynamic error correction models, which account for heterogeneous transmission mechanisms among federal states and the presence of unobserved common factors such as global macroeconomic shocks. Our findings hint at a significantly negative relationship between regional public debt and per capita GDP in the long run. We further demonstrate that this negative long-term effect is not negligible for the interregional differences in per capita GDP levels. Linking our empirical findings to the current policy debate on fiscal consolidation, we show along the lines of the German case that the decision of enacting a constitutional debt brake for subnational governments to limit the degree of discretionary spending policies together with supplementary measures - such as joint capital market operations by the central and state-level governments to lower borrowing costs - may provide new stimuli for a European-wide debate on the feasibility of solid fiscal consolidation.