Some analysts believe that in the long-term, countries like Germany with ageing populations stand to gain from an influx of (largely younger) immigrants.
"In principle, fast-aging Europe could well benefit from the arrival of young, often relatively well-educated migrants, but the mixed success of many European countries in integrating migrants highlights that such economic benefits are by no means automatic," said Citi analysts led by Tina Fordham in a report this month.
However, the costs in the short-term are "clearly significant," Daniel Morris, senior investment strategist at BNP Paribas, told CNBC on Friday.
"You can imagine it is just going to get more challenging as we move into Autumn and Winter. I mean right now, at least you have got decent weather for these people, but imagine the situation in December," he said.
Alistair Newton, formerly of Nomura and now director of Alavan Business Advisory, concurred. "At best, we therefore look to be in for a long and difficult haul, which warrants careful attention from investors given what I see as the inherent downside risks," he said in a research note on Friday.