We simulate numerically a trade model with labor mobility costs added, modeled in such a way as to generate gross flows in excess of net flows. Adjustment to a trade shock can be slow with plausible parameter values. In our base case, the economy moves 95% of the distance to the new steady state...

Limited consumer attention limits product market competition: prices are stochastically lower the more attention is paid. Ads compete to be the lowest price in a sector but compete for attention with ads from other sectors: equilibrium ad shares follow a CES form. When a sector gets more...

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...

Equilibrium prices behave quite differently if consumers single-purchase (buy either Time Magazine or Newsweek) or if some consumers multi-purchase (buy both). Prices are strategic complements under single-purchase, and increase with magazine quality. In a multi-purchase regime prices are...

This paper shows that governments have no incentive to introduce non-tariff 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 u sing tariffs only to quotas,...

Advertising messages vie for scarce attention. “Junk” mail, “spam” e-mail, and telemarketing calls need both parties to exert effort to generate transactions. Message recipients supply attention depending on average message benefit, while senders are motivated by profits. Costlier...

Advertising competes for scarce consumer attention, so more profitable advertisers send more messages to break through the others' clutter. Multiple equilibria can arise: more messages in aggregate induce more "shouting to be heard", dissipating profit. Equilibria can involve a small range of...