Plant Life Cycle And Aggregate Employment Dynamics

Past empirical studies have repeatedly found that plant age matters for aggregate employment dynamics. This paper develops a model of plant life cycle to capture this empirical regularity. In the model, plants differ by vintage and by idiosyncratic productivity. The idiosyncratic productivity is not directly observable, but can be learned over time. This setup gives rise to a learning effect and a creative-destruction effect, under which labor flows from plants with low idiosyncratic productivity to those with high idiosyncratic productivity and from old vintages to new vintages. When calibrated to the U.S. manufacturing job flow series, our model of plant life cycle delivers the observed link between plant age and aggregate employment dynamics.