5. Conclusion
This paper considers the implications of allowing firms to be sophisticated enough to design product lines. Such a level of sophistication makes them interested in consumer level information, and the distribution of income in particular. Enriching firm behavior in this way results in a tractable model and provides a link between the distribution of income and the gains from trade.
This link arises as firms implicitly discriminate between the various income classes, which in equilibrium results in a product line that differs from what a utilitarian social planner would choose. Since the distortions are largest at the lower end of the income distribution, this is where the consequences of international integration are also most pronounced. Trade can reduce these distortions in countries whose income distributions dominate the global distribution, while amplifying them in countries that are dominated.
This structure implies that the impact of integration is even more pronounced under a process of gradual liberalization since the variety and design dimensions of welfare respond differentially to the level of trade barriers. In particular, design changes occur disproportionately at lower trade barriers, with the potential to derail the process of trade liberalization. Quantifying the relative importance of this mechanism suggests that it is a legitimate issue that could significantly complicate future integration efforts.