BRUSSELS -- The European Union is predicting that 3 million migrants could arrive in the 28-nation bloc by the end of next year, with the refugee emergency already proving a stern test of EU border and reception capacities.
More than 700,000 people have come to Europe seeking sanctuary or jobs so far this year.
The arrivals are imposing costs for shelter, rescue operations and border security, but the EU estimates that the refugees are likely to bring economic benefits within a few years, notably in Germany, one of the preferred destinations for many people.
EU autumn economic forecasts released on Thursday show that based on current migrant entries and a "technical assumption" about future flows, arrival rates for migrants are unlikely to slow before 2017.
The EU's executive Commission said that "overall, an additional 3 million persons is assumed to arrive in the EU over the forecast period."
Greek Prime Minister Alexis Tsipras was a first-hand witness to the arrivals on Thursday, as migrants and refugees reached the island of Lesbos by dinghy while his motorcade travelled from Lesbos airport to a new registration facility.
"We realized that is a criminal process being carried out by the smugglers who cram refugees onto vessels that are not boats, but makeshift inflatables," he said. "What's happening in the Aegean Sea is a crime."
The flow of migrants into Greece's mainland and beyond was turning to a trickle on Thursday, however, as a ferry strike entered its fourth day and trapped thousands of people on the eastern Aegean islands.
Police in the Idomeni border area said 850 people had crossed into Macedonia between Wednesday and Thursday morning. Numbers usually range from 4,000 to 8,000 people per day. The strike is set to end Friday.
Despite the figures of refugee increases, the European Commission predicted that the population across the 28 EU nations would only rise by about 0.4 per cent. No obvious impact on employments levels is likely, it said.
"You cannot say that this influx of refugees is likely to have a negative impact, or some kind of a shift of kicking other people out of the labour market," the EU's top economics and finance official, Pierre Moscovici, said.
However the EU said the real impact on national budgets is difficult to predict, given a lack of complete and reliable data about exactly who is arriving in the bloc and whether they are staying.
Most people are arriving in Europe through Italy and Greece, while Hungary and Austria have been affected by heavy migrant flows. Germany and Sweden are also feeling the impact.
Those nations, among others, want the EU to apply its budget rules with flexibility, taking into account Europe's biggest refugee emergency in well over half a century, and avoid reprimanding member states for excessive spending and deficits.
The Commission said Thursday that Sweden, which has the highest share of refugees per capita and wants its EU partners to host some of the refugees arriving on its territory, is likely to feel the economic impact most, perhaps 0.5 per cent of its gross domestic product this year.
Other hard-hit migrant transit and destination countries are likely to see an impact of 0.2 per cent of their GDPs in 2015, but Brussels pointed out that Germany and others would benefit in coming years from a boost in spending and the creation of more jobs.
While acknowledging the potential short-term impact, the Commission did not clearly state whether it would be lenient on any country with budget problems.
However a senior EU official said on Wednesday that some flexibility might be allowed "taking into account well-specified costs and for a limited period of time."
"This has been an asymmetrical shock for some member states," said the official, briefing reporters on condition that he not be named.
As long as any help is "one-off, shortish-term," members of the euro single currency bloc would agree to it, he said.
