Examining the relationship between immigration and unemployment

"Our results, which appear robust to different specifications, different levels of geographic aggregation, and to a number of tests, seem to confirm the lack of any impact of migration on unemployment in aggregate. We find no association between migrant inflows and claimant unemployment. In addition, we test for whether the impact of migration on claimant unemployment varies according to the state of the economic cycle. We find no evidence of a more adverse during periods of low growth or the recent recession."

http://niesr.ac.uk/publications/examining-relationship-between-immigration-and-unemployment-using-national-insurance#.UsvhgPTMR8F