We derive a new formula for the optimal uniform tariff in a small-country, heterogeneous-firm model with roundabout production and a nontraded good. Tariffs are applied on imported intermediate inputs. First-best policy requires that markups on domestic intermediate inputs are offset by subsidies. In a second-best setting where such subsidies are not used, roundabout production and the monopoly distortion in the traded sector create strong incentives to lower the optimal tariff on imported inputs. In a quantitative version of our two-sector small open economy, we find that the optimal tariff is lowered under nearly all parameter values considered, and can be negative.
We develop a dynamic multicountry general equilibrium model to investigate forces acting on the global economy during the Great Recession and ensuing recovery. Our multisector framework accounts completely for countries' trade, investment, production, and GDPs in terms of different sets of shocks. Applying the model to 21 countries, we investigate the 29 percent drop in world trade in manufactures during the period 2008-2009. A shift in final spending away from tradable sectors, largely caused by declines in durables investment efficiency, accounts for most of the collapse in trade relative to GDP. Shocks to trade frictions, productivity, and demand play minor roles.