I found this special report in the Economist last month, and was meaning to comment on it here.  I am not surprised by the general optimistic tone of the report, and being an immigrant myself I'm probably not the most impartial person to comment on its benefits for the immigrant, the origin and host countries.

One thing that I would like to bring to the fore, is however, the backlash against immigration and immigrants currently going on in many places around the world.  Given that many people don't see the benefits for them, they strongly oppose it, with sometimes rather ugly attitudes showing up.