This thesis addresses the issue of policy effects on domestic and international migration, considering in particular the case of Mexican migration. The first essay investigates the effect of U.S. border enforcement on the net flow of Mexican undocumented migration. Such effect is theoretically ambiguous, given that increases in border controls deter prospective migrants from cross ing the border illegally, but lengthen the U.S. permanence of current ones. It estimates border enforcement's net impact on migration inflow using a sample of potential and current illegal migrants. U.S. border enforcement significantly reduces the net flow of undocumented migration. However, the reduction in net flow is more than half the size of the decrease in inflow. The second essay models the short and medium-run impact of aid on migration, considering alternatively the effect of unconditional and conditional cash transfers to financially constrained households. Data from the evaluation of a Mexican development program, Progresa, are used to estimate the effect of the grant on migration. The empirical analysis shows that the program is associated with an increase in international migration, which is also a positive function of the potential transfer size. Conditional grants in the form of secondary school subsidies reduce the short-term migration probability. Progresa does not seem to increase medium-term migration. The final chapter reviews the approaches employed to estimate Treatment on the Treated Effects (TTEs) using experimental data in the presence of non-compliers. It discusses the types of parameters that can be identified using the Progresa data. It uncovers new parameters that have not been estimated so far, based on the fact that a group of eligible households did not receive the program transfer in the initial stages of its implementation. It proposes alternative estimating procedures to identify counterfactuals in the presence of non-compliers for users of the Progresa data. It complements the theoretical part with an empirical application by estimating the effect of Progresa on school enrolment.

This thesis analyzes the role of the Immigration Restriction League in the political regulation of immigration in United States between 1894 and 1924. The League promoted the exclusion of the so-called new immigrants, assumed to be not ‘fully white’ and therefore inferior to Anglo-Saxons. Similar to other progressive movements, the League’s activities included the scientific investigation of a problem, the creation of public awareness and, eventually, the implementation of solution through legislation and government agencies. Based on a wide range of source material, the thesis investigates the IRL’s engagement in the racialization of the new immigrants, its interaction with eugenicists, other progressive reformers and state agencies involved in research on immigrants and border control. The League’s activities are interpreted as a biopolitical and governmental project at the intersection of political self-regulation, the construction of racial identities and the increasing power of the modern nation-state to control and regulate the population. The thesis argues that the IRL can be understood as an example for a changing mode of power in the progressive era that relied on its citizens’ participation in the optimization of the state. Since the League equated the American state with the supposedly superior Anglo-Saxon race, it concentrated on informing other white citizens of the putative racial threat posed by the new immigration. Compiling and interpreting statistical data, the IRL argued that new immigrants were more likely to be criminal, insane or paupers due to inherent racial characteristics. It thus appealed to citizens, educators, scientists, reformers and politicians to engage in the protection from this threat, resulting in stricter border controls, the passage of a literacy test and the establishment of the quota system.

This thesis sketches out the history of Ottoman-Arab emigration from Greater Syria to the United States and to Argentina from the late nineteenth century up to the end of World War I, relying primarily (but not solely) on the related documents preserved in the Ottoman Archives. It depicts a wide range of this emigration history, including the scale and the number of immigrants, the causes behind emigration, the ways that emigrants managed to reach the Americas, the attitudes of Ottoman governments toward them, and the ways that emigrants adapted to their host societies. The thesis analyses the Ottoman-Arab emigration phenomenon from social and economic perspectives and in the larger context comprising other European population movements to the New World during this period, which has been called 'the Age of Mass Migrations'.