In this paper, we present a standard quality ladders endogenous growth model with one significant new assumption, that it takes time for firms to learn how to export. We show that this model without Melitz-type assumptions can account for all the evidence that the Melitz (2003) model was...

We analyze recent contributions to growth theory based on the model of expanding variety of Romer (1990). In the first part, we present different versions of the benchmark linear model with imperfect competition. These include the "lab equipment" model, "labor-for-intermediates" and "directed...