The first chapter investigates the possible ways that religion influences international trade patterns. Using a gravity equation approach the chapter finds that religions have different impacts on trade and that religious openness boosts the trade performance

Chapter 2 develops a simple theoretical model that includes vertical product differentiation in a heterogeneous firms' trade model. The model yields several predicitons for which strong empirical support is found using detailed export data

The main purpose of chapter 3 is to develop a method to improve the estimation of border effects using data on regional transportation flows. Applying this method to the case of France and Germany our results indicate that both countries exhibit a strong border effect

The laste chapter examines the impact of a reform of a preferential market access scheme on textiles and clothing exports of Least Developed Countries. It yields evidence that the reform substantially improved these countries' exports