This thesis contributes to three debates in international economics: (i) the integration process of migrants' communities; (ii) the role of economic institutions in international trade and (iii) the determinants and the effects of services trade policy. For different reasons, all debates are high on the global governance agenda. The phenomenon of international migration leads to the existence of disadvantaged minorities within mature host economies. The social cohesion in the recipient countries as well as the general attitude toward further international mobility depend upon the policy capacity to govern the integration of migrant communities. In the first chapter of the thesis I offer a positive analysis of integration policies with a specific focus on the labor market. As for the second debate, recent studies have shown that economic institutions such as contract enforcement, regulatory quality and the like are important determinants of trade patterns as well as crucial factors shaping the effects of trade policy. The second chapter of the thesis contributes to this literature looking at the role of contract enforcement in a trade model with heterogeneous firms, endogenous firm organization and institutions-driven comparative advantage. We find that, in countries with a fragile institutional framework, aggregate productivity might not benefit from the reallocation of resources due to trade liberalization. The third chapter carries on with the analysis of institutions introducing the third debate on services trade. In particular, we demonstrate empirically that, under weak institutions, lower restrictions to trade in services fail to benefit the manufacturing sectors that use services as intermediate inputs. Trade in services has surged but high restrictions remain. Little has been done to understand the determinants of services trade commitments. In the fourth chapter of the thesis we identify the degree of services input intensity into a national economy as an important factor behind the willingness to commit to services trade openness.