Productivity Growth
Investing in recession?

Recent empirical studies of the cyclical behaviour of job creation and job destruction have found that destructions are concentrated in recession periods, while creations are subject to relatively smaller fluctuations over the cycle. In Discussion Paper No. 578, Research Fellows Philippe Aghion and Gilles Saint-Paul formalize the idea that economic fluctuations can stimulate productivity growth with a simple model in which firms' investment in such growth in the reorganization of their production or in technical progress is greater during recessions that are expected to be followed by an expansionary phase. Productivity growth increases because the opportunity cost (in terms of forgone profits) of investing capital or labour resources in technological improvements or managerial reorganizations is low during depression phases the more so when the discrepancy between booms and slumps is large.
Aghion and Saint-Paul first study a one-firm (or one-sector) model, in which the sole producer decides at each instant how to distribute labour between reorganization (or R&D) and production activities. They find that the average growth rate is an increasing function of the amplitude of the economic fluctuations which are assumed to occur randomly and increases with the frequency of recessions, provided that the latter are initially less frequent than expansionary phases. For a multi-firm (or multi-sector) version of this model, in which firms are subject to uncorrelated idiosyncratic shocks of the same type, they find that the average growth rate again depends on the amplitude and frequency of fluctuations. The growth process introduces an additional discounting effect, however, which works through relative prices over time to an extent that increases with the intersectoral substitutability of products.
Aghion and Saint-Paul then analyse the combined effects of idiosyncratic fluctuations and aggregate recessions, which they find reinforce one another the more so when firms incur (large) fixed production costs. More generally, large fixed production costs tend to increase the impact of economic fluctuations on growth. Finally, they show that under a natural interpretation of the model where firms continually hire or fire workers for both `reorganization' and `production' activities their main results are consistent with those found in recent empirical evidence on the cyclical behaviour of job reallocation.

On the Virtue of Bad Times: An Analysis of the Interaction Between Fluctuations and Productivity Growth
Philippe Aghion and Gilles Saint-Paul

Discussion Paper No. 578, October 1991 (IM)