Two interesting papers here and here from National Institute for Economic and Social Research, on the effect of migration within Europe.
Also an interesting factoid: 11.6 per cent of 25-34 year olds in the UK have arrived since 1997. (some of them are in the OE office)
Interestingly, NIESR are much more pessimistic about unemployment than the Home Office. In their modelling experiment 500,000 people arriving in the UK over five years (rather slower than the real rate so far) is predicted to cause unemployment to rise by 0.4 - 0.5%
Meanwhile in Poland: "There is likely to be a decline in the unemployment rate during the first five years after the emigration shock and productivity growth would increase over this period, as employment declines more rapidly than the capital stock can adjust so the capital–labour ratio rises markedly, albeit largely temporarily."