Current Migrations Research Articles

US Border Enforcement and the Net Flow of Mexican Illegal Migration

I investigate the effect of US border enforcement on the net flow of Mexican undocumented migration, both of which have been considerably increasing in the last 3 decades. This effect is theoretically ambiguous, as increases in border controls deter prospective migrants from crossing the border illegally but lengthen the duration of current illegal migrations. The inflow and outflow of illegal Mexican migration respond to changes in border enforcement. The marginal effect of enforcement on the inflow increases with enforcement and is consistent with the hypothesis that tighter enforcement selects more productive migrants. This positive selection makes the outflow sensitivity to marginal enforcement changes comparatively more stable over time. A marginal increase in border controls increases the stock of undocumented migrants between 1972 and 1986, has either no effect or a small and negative effect between 1987 and 1996, and has a larger and significant negative effect between 1997 and 2003.

U.S. Border Enforcement and the Net Flow of Mexican Illegal Migration

This paper investigates the effect of U.S. border enforcement on the net flow of Mexican undocumented migration. It shows how this effect is theoretically ambiguous, given that increases in border controls deter prospective migrants from crossing the border illegally, but lengthen the duration of current illegal migrations. It then estimates the impact of enforcement on 1972-1993 migration net flows by merging aggregate enforcement data with micro data on potential and current illegal Mexican migrants. The econometric model accounts for the endogeneity of border controls using the Drug Enforcement Administration budget as an instrumental variable. Both the inflow and outflow of illegal Mexican migration are highly sensitive to changes in border enforcement. The estimates of the enforcement overall effect on illegal migration's net flow range across different specifications, from a decline - about 35% of the size of the effect on the inflow - to an increase. Thus, they suggest that border enforcement may not be an effective means to reduce the level of the illegal alien population in the United States.

Les migrations soninkées dans la longue durée : stratégies et identités

Abstract Soninke Migrations in the Long Run : Strategies and Identifies. — This review article places two studies of Soninke migrations in perspective. F. Manchuelle's historical study emphasizes the relations between current migrations and older activities over a long period of time. It shows how migrations developed under colonialism and draws attention to extra-economic factors underlying them. M. Timera's work deals with different aspects of contemporary Soninke migrations to France: dormitory life, arrangements for bringing families, Islam and work. With the settling of migrants and the emergence of the "second generation" of their children, new strategies are at work and new identities corne into play, but without any break taking place with the homeland.

14C Dating of Late Pleistocene–Holocene Events on Kunashir Island, Kuril Islands

Kunashir Island is a very important site for paleoenvironmental reconstructions. Until recently, very little information on Quaternary deposits was available. We studied the environmental evolution of this oceanic island under the influence of geomorphological processes, volcanism and strong marine currents. This paper presents new data that allow a detailed reconstruction of the environmental development of Kunashir Island during the Late Pleistocene–Holocene, based on ca. 80 radiocarbon dates and diatom, pollen and sedimentological data. The vegetation development reflects climate changes and warm/cold current migrations.