Constant immigration can stabilize population size fluctuations but its effects on extinction remain unexplored. We show that constant immigration significantly reduced extinction in fruitfly populations with relatively stable or unstable dynamics. In unstable populations with oscillations of amplitude around 1.5 times the mean population size, persistence and constancy were unrelated. Low immi...

Disturbances are expected to increase variability and/or decrease predictability in ecosystems, while dispersal (or immigration) may have positive or negative effects on ecosystem stability. We conducted a mesocosm experiment with pelagic zooplankton to examine the independent and interactive effects of a nutrient pulse and immigration from neighbouring lakes on (a) temporal variation in the me...

The importation of foreign registered nurses has been used as a strategy to ease nursing shortages in the United States. The effectiveness of this policy depends critically on the long-run response of native nurses. We examine the effects of immigration of foreign-born registered nurses on the long-run employment and occupational choice of native nurses. Using a variety of empirical strategies ...

This paper considers the relationship between economic factors and national security. While considering a broad number of issue areas, the principal theme of the course is the way in which economic factors (as immigration) fundamentally influence the national security of the region, and the way in which those factors shape and constrain the strategies chosen to pursue that security. South-South...

British population history has been shaped by a series of immigrations, including the early Anglo-Saxon migrations after 400 CE. It remains an open question how these events affected the genetic composition of the current British population. Here, we present whole-genome sequences from 10 individuals excavated close to Cambridge in the East of England, ranging from the late Iron Age to the midd...

This study investigates the effects of the macroeconomic context on attitudes to immigration. Earlier studies do in some cases not provide significant empirical support for the existence of important such effects. In this article it is argued that this lack of consistent evidence is mainly due to the cross-national setup of these studies being vulnerable to estimation bias caused by country-spe...

Education usually shows a relationship with self-rated health such that those with highest education have the best health and those with lowest education have the worst health. We examine these educational gradients among Asian immigrants and whether they differ by country of origin, duration in the United States, and generational status. Migration theories suggest that recent immigrants from p...