We fully solve an assignment problem with heterogeneous firms and multiple heterogeneous workers whose skills are imperfect substitutes, that is, when production is submodular. We show that sorting is neither positive nor negative and is characterized sufficiently by two regions. In the first...

During its early and formative years, the U.S. tire industry was heavily concentrated around Akron, Ohio. We test the extent to which entrants in Ohio were attracted to the Akron area by agglomeration benefits, contributing to a self-reinforcing process envisioned in many modern theories of...