Standard media economics models imply that increased platform competition decreases ad levels and that mergers reduce per-viewer ad prices. The empirical evidence, however, is mixed. We attribute the theoretical predictions to the combined assumptions that there is no advertising congestion and...

This survey reviews research on how workers and labor markets respond to trade shocks, with an emphasis on recent and ongoing work and on dynamic rather than static analysis. Some studies estimate rich models of worker behavior, while others simplify the worker's problem to embed it in a rich...