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 paper shows that governments have no incentive to introduce nontariff barriers when they are free to set tariffs but they do when tariffs are determined cooperatively. We then show three results. First, with trade liberalization, there is a progression from using tariffs only to quotas, and...