We investigate the role of skill complementarities in production and mobility across cities. The nature of the complementarities determines the equilibrium skill distribution across cities. With extreme-skill complementarity, the skill distribution has thicker tails in large cities; with...

We propose a theory of firm production that requires diverse inputs. We show that in a competitive labor market, firms differ in their skill composition. Organizations with higher total factor productivity (TFP) are larger and hire from a broader range of skills. Technological progress leads to...

Workers in less-secure jobs are often paid less than identical-looking workers in more secure jobs. We show that this lack of compensating differentials for unemployment risk can arise in equilibrium when all workers are identical and firms differ only in job security (i.e. the probability that...