This chapter examines several key issues in the "polarization" debate. Should one be using wage or income data, and before or after income tax? How refined are aggregate countrywide job classifications when job tasks essentially differ by firms? Is polarization a universal phenomenon, or is it...

We develop an empirical framework to assess the importance of trade and technical change on the wages of production and non-production workers. Trade is measured by the foreign outsourcing of intermediate inputs, while technical change is measured by the shift towards high-technology capital...