Abstract : Despite a strong drop in tariff barriers in the second half of the twentieth century, numerous empirical studies have shown that international trade flows are affected by sizeable trade costs.
These trade barriers create an international market segmentation, affecting the open macroeconomic equilibrium. Yet, almost all macro models ignore this reality, assuming a perfect integration of international markets.
In this thesis, I study the implication of market segmentation in several aspects of the open macroeconomic equilibrium. To this aim, I use tools of The New Trade Theory. This literature underlines the role of trade costs in explaining international trade and foreign investment flows, when taking into account firms' strategic behaviour in a global framework.
The first part of the thesis focuses on the consequences of market segmentation on exporting firms' pricing behaviour. The empirical analysis based on disaggregated data underlines the micro determinants explaining the low aggregate sensitivity of trade prices to exchange rate movements.
The second part introduces firms' location strategy in the analysis and investigates its impact on the relative price level. It explains how the entry of new firms in a national market exerts a downward pressure on its aggregate price level. Last, the third part of the thesis examines the
consequences of endogenous location decisions on the efficiency of economic policies. In particular, it shows how national minimum wage policies affect the spatial distribution of firms, through the channels of relative production costs and aggregate demand.