The EU migrant policy is a tricky one, as its fairly well established that migrants have a short-term economic impact which is at best neutral and more often slightly negative.
However, beyond that term, and I mean 30+ years beyond, they have a positive impact. They increase the population, and large populations normally mean a larger economy, with a larger tax base. Immigrants and second and third generation immigrants are often highly incentivised to succeed and outperform the host population in academic achievements and earning power. They may bring assets with them, which is a bonus, but more likely they offer an immediate pool of low cost labour which is unrooted within Europe and free to transfer wherever there is work. They generate children faster than the indigenous European population, which accelerates population growth. When they acquire voting rights, they are highly likely to support the (usually leftist) governments which admitted them, and cetainly the EU itself as a framework, whereas they are not highly committed to any particular nation states within Europe. To some extent they are also hostages to an EU structure with continuing benign migration policy as they wish to bring spouses and relatives into the EU in future years when they are established: it certainly appears that few national governments are keen on uncontrolled immigration so why would the migrants or their descendants vote in any way for continuing European states?
So there are three main benefits to a committed EU-believer - economic, political and anti-nation state. They will be a large and fast-growing voter body which will support the EU in its quest to abolish individual European states and unite Europe.
This only makes sense on a 50-100 year time-frame, but I have tried to emphasise that the EU is not a trading association with its profit-driven short-termism - it is a historic political project and in that context the migrant policy is totally rational.
Well put and most likely the reason why there is a large, growing resistance to the EU across Europe. On a 50-100 year timescale, it is a frightening prospect to many citizens that the nation states of Europe will 'disappear' as a direct result of EU mass migration policies, replaced by the dreaded political 'I' ideology (dreaded not just because no-one dare speak about such a word for fear of being labelled, but also because of what it represents), this idea alone is driving many to oppose the EU.
Modern migrants are not the same as those from 50 years ago, the 'windrush era' were hard working commonwealth citizens, with great work ethics, family orientated, adopted host nations culture whilst integrating thier own cultures and instilled a greater work and achievement ethic in their offspring.
The latest migrants appear not to be the same at all, a mixed bag of pre-westernised consumers and religious freakery, with little regard for citizen's rights of host nations, no family values, corrupt in various forms, feral and bringing tribal conflicts with them and an aggressive resistance to integrate with host cultures. There are genuine refugees of course, but it doesn't appear that they make up the majority, we all lose out under these circumstances.
The fate of the EU is at a juncture, there are no signs that the central command of the EU is going to change it's course of action, quite the opposite, therefore it is left to the citizens to act at the ballot box. The race is on, if the EU is able to import enough future voters they will maintain their domination, albeit morphed into something probably unrecognisable to what we see today, otherwise indigenous citizens may save themselves from themselves.
Closer to home, you have already seen the same playbook operate in major cities in the UK where the minority vote aligns mostly with the left to become the majority, aided by the left of course, and those areas have all turned red (left-wing). The conservative right also seems incapable of making a stand for their own traditional values and has progressively also moved left, where do we go from here?
Oh dear, what a mess this has become, it was going so well until political union, the economics are really a side show in this context.
