Aggregate dynamics and microeconomic heterogeneity: the role of vintage technology

We study how the timing of technology adoption through capital accumulation shapes firm-level productivity dynamics and quantify its aggregate implications in a model of heterogeneous firms. Using data on the census of incorporated Italian firms and exploiting the lumpiness of capital accumulation, we document that large investment episodes lead to productivity gains at the firm and sectoral level due to vintage effects. In a general equilibrium model of firm heterogeneity, we find that the presence of vintage technology constitutes a powerful microeconomic-based amplification mechanism of aggregate shocks relative to a benchmark real business cycle model.