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 “labequipment” model, labor-for-intermediates” and...

This paper explains why trade liberalizations occur in developing countries, and why they are often reversed. It does so by focusing on the use of lobbying for protection by import competing firms as a means to postpone costly product quality upgrades to keep up with foreign competitors. Given...