The challenge with immigration policies

From the comments section of an article by John Kay in the context of the recent proposal by UK government to limit immigration,

I've lived in a part of London, not a fashionable part but to me a wonderful part, where there used to be a huge diversity of small businesses and workshops. We even had several small farms providing fresh produce of all kinds including poultry, dairy and meat. We used to have our local dairy, bakeries, woodshops, foundries, printers, brickfields, artistic businesses of various kinds and small manufacturers making components and glass ware. It used to be great walking around and seeing what was being done and made. There used to be no unemployment in our district.

Since the 80's these small businesses have increasingly sold out because the land on which they were working became so valuable and goods from abroad so cheap that one by one the businesses folded. Now you can get very little locally and many if not most people shop in malls, out of town supermarkets and online. You cannot buy locally baked bread anymore or fresh eggs or locally sourced veg, fruit and meat as you could just a decade ago.

As developers took over a higher and higher proportion of our land they built smaller and smaller housing units in dense, soulless housing estates which had none of the quality of the Victorian housing which used to dominate. In fact most of our iconic historical buildings have vanished to be replaced by high rise flats. It is heart breaking to see this happening.

As the businesses and open land vanished more and more immigrants from all over the world came into our borough because it was their first port of call on arriving here. I have nothing against them because they are people, just like us natives. They too have to deal with the massive development and loss of character and choice which we used to have. It is not their fault that our borough has been ruined and now depends on ever less eco friendly consumption through the usual supermarkets and other outlet stores. But I do wish we had the businesses back instead of the wave of immigration. Local businesses are green and allow the ordinary person to have a living within distance of their home and it cuts down on costs and disadvantages of goods coming a long way.

This captures the essence of the immigration problem as seen by those affected. No amount of sermonizing about the aggregate benefits of immigration, confirmed by rigorous research, can clear this impression. It is therefore only natural that political leaders, the vast majority of whom realize its possible net beneficial effects, reflect the concerns of their affected electorate.

Even when their overall effect is beneficial, real people, and large numbers, lose heavily in the process of globalization and liberalization. It is only prudent that any efforts to promote them should therefore necessarily be accompanied by policies that directly seek to cushion those adversely affected.

Instead of the interminable debates and research about the effects of immigration, we should be more concerned about the design of policies that can attenuate the adverse impacts of these trends. What should be the nature of policies that cushion the victims? What should be the extent of social safety protection policies? What should be done to reintegrate those affected back into the mainstream? How should such policies be financed? How much should the winners of these trends compensate the losers?

The same logic applies not only to population groups within countries but also changes in multilateral regimes that often hurt countries as a whole.