Endogenous Growth, Firm Heterogeneity and the Long-run Impact of Financial Crises

I propose a new endogenous growth model with heterogeneous firms and aggregate shocks. The model shows that firm heterogeneity generates several new amplification and persistence mechanisms for a transitory shock to financing conditions. This shock imposes financing constraints, which force small and young innovating firms (with low retained earnings) to reduce their R&D, and therefore leads to R&D misallocation. Furthermore, it lowers entry and persistently reduces the mass of innovating firms. Thus, even as financing constraints disappear, aggregate R&D and innovation remain persistently depressed, as the remaining large firms can only imperfectly substitute for the R&D of the missing generation of young and small ones. Finally, lower R&D during and after the shock also limits the scope for incremental follow-up innovations. My model's main features are in line with developments in the Spanish manufacturing sector during the 2008-2013 economic and financial crisis.