Gravity as both fact and theory is one of the great success stories of recent research on international trade, and has featured prominently in the policy debate over Brexit. We first review the facts, noting the overwhelming evidence that trade tends to fall with distance. We then introduce some...

We use stochastic optimal control-dynamic programming (DP) to derive the optimal foreign debt/net worth, consumption/net worth, current account/net worth, and endogenous growth rate in an open economy. Unlike the literature that uses an Intertemporal Budget Constraint (IBC) or the Maximum...

Bilateral trade balances often play an important role in the international trade policy debate. Academic economists understand that they are misleading indicators of competitiveness and of the gains from trade. However, they also recognize their political relevance, calling for accurate...

Bilateral trade imbalances are determined by aggregate trade imbalances, production and expenditure patterns, and trade barriers. We calibrate a dynamic many-sector trade model to match the recent sectoral trade and production shares of 40 economies and the rest of the world. Through a variance...

What is an optimal or a sustainable external debt - for a country, region or sector? How should one monitor and evaluate debt to preclude a crisis? We use stochastic optimal control/dynamic programming to derive an optimal debt. The deviation of the actual from the optimal will serve as a...

We propose new methods to identify the full impact of country-specific characteristics on bilateral trade flows within the framework of ‘the new quantitative trade model.' We complement theory with a simple two-stage estimating procedure, and offer a proof of concept by quantifying the impact...

Estimates of the trade elasticity based on actual trade policy changes are scarce, and the few that exist are all over the place. This paper offers a setting where an exogenous increase in a border tax can be used to estimate the trade elasticity. It shows theoretically and empirically that if...

How do trade costs affect international trade? This paper offers a new approach. We rely on a flexible gravity equation that predicts variable trade cost elasticities, both across and within country pairs. We apply this framework to the effect of currency unions on international trade. While we...

Trade elasticity is a crucial parameter in evaluating the welfare impacts of changes in trade frictions. The value of this parameter varies widely across product categories, however, which is especially important for developing countries' evaluation of the welfare gains from trade. We estimate,...

We propose a simple and flexible reduced-form econometric approach to estimate gravity models in the short and the long run. The theoretical lens for interpreting our methods amends the canonical Lucas-Prescott adjustment formulation to allow for time-interval-varying...