We present a gravity model that accounts for multilateral resistance, firm heterogeneity and country-selection into trade, while accommodating asymmetries in trade flows.  A new equation for the proportion of exporting firms takes a gravity form: the extensive margin is also affected by...

We show that relaxing the assumption of CES preferences in monopolistic competition has surprising implications when trade is restricted.  Integrated and segmented markets behave differently, the latter typically exhibiting reciprocal dumping.  Globalization and lower trade costs have...

This paper analyses the effects of trade liberalisation and technical change on real and relative wages.  It builds a model with monopolistic competition, heterogeneous firms and two countries, North and South, and solves it numerically.  Skill-biased technical change, caused by decreases in...

We introduce two new tools for relating preferences and demand to firm behavior and economic performance.  The "Demand Manifold" links the elasticity and convexity of an arbitrary demand function; the "Utility Manifold" links the elasticity and concavity of an arbitrary utility function. ...

We provide a general characterization of which firms will select alternative ways of serving a market.  If and only if firms' maximum profits are supermodular in production and market-access costs, more efficient firms will select into the activity with lower market-access costs.  Our result...

Shipping goods internationally is risky and takes time.  To allocate risk and to finance the time gap between production and sale, a range of payment contracts is utilized.  I study the optimal choice between these payment contracts and their implications for trade.  The equilibrium contract...

I present a trade model featuring North-South differences in demand for quality and in quality of task supply.  The model explains a number of stylised facts: Southern firms charge higher factory-gate prices for their products in rich than in poor, and in distant than in near markets.  The...

We analyse the costs of a monetary union in West Africa by means of asymmetric aggegate demand and aggregate supply shocks. Previous studies have estimated the shocks with the VAR model. We discuss the limits of this approach and apply a new technique based on the dynamic factor model. The...

This paper discusses the place of oligopoly in international trade theory, and argues that it is unsatisfactory to ignore firms altogether, as in perfectly competitive models, or to view large firms as more productive clones of small ones, as in monopolistically competitive models.  Doing...

We present a new model of multi-product firms (MPFs) and flexible manufacturing and explore its implications in partial and general equilibrium. International trade integration affects the scale and scope of MPFs through a competition effect and a demand effect. We demonstrate how MPFs adjust in...