@Blue Marlin
Oh...I got the answer at the first thought, I only ask to be sure because i couldn`t believe it.
You are a optimist, me seems, I hope it, but i don`t believe it and to be honest, I can`t hear this anymore. The economic answer...there is more than economy. But we could this reduce to economy.
Language, the migration waves to the UK were mostly from their former colonies and they already were able to speak English...how many migrants are able to speak German nowadays?
Education, I haven`t the exactly data about the education levels of the migrants in the 60`, but we have some data now. The truth is, we got or did not get the doctors and engineers who are trying the media and politicians to sell us and that is the next point. You could earn money and live with them in the 60`, but you need more skills in an high tech society like ours, welcome in the year 2016.
What we would be at the point of cheap labor, as if this would not market already crowded with us and constantly grow. For more, it will not bring the majority of migrants, I do not want reduced these people, it`s just so. The digitization and automation supplant the muscular power and require knowledge not muscles. The Tale of labor shortages with us is the pure joke.
The next point for this post...the attitude of the migrants nowadays. It seems to me, the majority of them is awaiting a house, studium, good job and a wife...in opposite to the migrants in the 60`, who know, they have to work for it.
We are faced with huge costs, official figures speak of 98 billion by 2020 and would require, it would come no new migrants. Money which is missing to expand our infrastructure, which of course reduces our competitiveness for the future. And finally, the whole boom is currently funded with taxpayers' money and debts and not sustained enough to carry itself ... I love it.
There is more but I will make you think for the answer...