This paper examines the effect of a technical change on the pattern of North-South trade in the presence of increasing returns to scale in production. The model shows that if the North initially takes advantage of the economies of scale in advance of the South, the relative wage will be higher...

We document that immigration to U.S. states has increased the mass of workers at the lower range of the skill distribution. We use this change in skill distribution of workers to analyze the effect of immigration on wages. Our model allows firms to endogenously respond to the immigration-induced...